gravity water supply system tools manual

Gravity Water Supply System Design Tools (v 2008.06) UNHABITAT, Afghanistan

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NOTICE

This manual “Gravity Water Supply System Design Tools” has been prepared to provide a basis for understanding and using spreadsheets and AutoCAD drawings prepared for designing community led gravity water supply systems in Afghanistan. Earlier versions of the spreadsheets have been in used by UN-HABITAT and other design engineers working in water supply projects. It is expected that use of these tools will result in a standard methodology for designing of gravity water supply sub-projects.

This manual and any examples contained herein are provided “as is” and are subject to change without notice. United Nations Human Settlements Programme (UNHABITAT) shall not be liable for any errors or for incidental or consequential damages in connection with the furnishing, performance, or use of this manual or the examples herein. © United Nations Human Settlements Programme (UNHABITAT). All rights reserved.

All rights are reserved to the programs and this manual that are included in the Gravity Water Supply System Design Tools. Reproduction, adaptation or translation of those programs and documents without prior written permission of UNHABITAT is also prohibited.

Gravity Water Supply System Design Tools (v 2008.06) is a shareware and can also be downloaded from www.fukuoka.unhabitat.org . Permission is granted to any individual or institution to use, copy, or redistribute the Gravity Water Supply System Design Tools so long as it is not sold for profit.

Published by:

United Nations Human Settlements Programme (UNHABITT), Afghanistan

House # 235, Street #8, Taimani,

Kabul, Afghanistan

Web: http://fukuoka.unhabitat.org

Email: [email protected]

Author:

Mr. Pushpa Chitrakar Engineering Advisor

UNHABITAT, Afghanistan

Printed by:

Afghan Women Entrepreneurs Printing Services,

Opposite Masjeed-e-Qahraman,

Karbala,

Kabul, Afghanistan

Tel: 0093- (0)700-285-709

This Edition:

June 2008

First Edition

500 copies

http://www.fukuoka.unhabitat.org

http://fukuoka.unhabitat.org

mailto:[email protected]


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PREFACE

The Gravity Water Supply System Design Tools (v 2008.06) were prepared by United Nations Human Settlements Programme, Afghanistan as a part of its continuous efforts to develop indigenous capacity of Afghan engineers engaged in rebuilding and upgrading Afghan rural as well as urban areas. It is a complete set of tools consisting of typical Microsoft Excel spreadsheets, AutoCAD drawings and procedural guidelines (this manual) for designing of community led gravity water supply projects. UN-HABITAT engineers working in nine provinces and Kabul have been using most of the presented spreadsheets for about a year. Since these tools have been verified by real engineering sub-projects, I personally found them very useful for the stated works.

Irrespective of the sizes and locations, all water supply projects have many common features from conception to implementation and operation. Therefore, these spreadsheets and drawings can also be used for all other similar projects within and outside Afghanistan.

I would like to thank all the members of the Engineering Division of UNHABITAT, Kabul for their supports to make this publication happen. My special thanks go to Mr. Pushpa Chitrakar, the Engineering Advisor of UNHABTAT, for his devotion on preparing such a set of useful tools. The contribution of all the UNHABITAT engineers working in all the nine provinces for their continuous support on the development of these tools is highly appreciated.

I do hope that these Gravity Water Supply System Design Tools would fill the gap that has been felt by all the engineering stakeholders and would be able to contribute to the sector.

Ms. Nouchine Yavari

Country Programme Manager



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ACKNOWLEDGEMENTS

Thanks for using the Gravity Water Supply System Design Tools (version 2008.06). It is a complete set of shareware tools consisting of twenty typical Microsoft Excel spreadsheets (a workbook), fourteen typical AutoCAD drawings and a users’ manual (this manual) recommended for use in detailed designing of community led gravity water supply system sub-projects. An electronic version of these tools (an Excel workbook and an AutoCAD drawing) and this manual in Acrobat PDF format are enclosed on the attached CD ROM.

Electronic versions of my other engineering tools are also enclosed on the attached CD ROM. The first one was made for designing micro-hydropower projects where as the second one was made for engineering surveying and discharge measurement.

Why I Prepared the Tools

I approached this project with one goal in mind. To write a one-step Gravity Water Supply System Design Tools that would appeal to all engineers engaged in implementing community led gravity water supply projects in Afghanistan. That is a fairly ambitious goal. But based on the feedbacks I received, I think I have been successful.

Microsoft Excel is the present market leader, by a long shot, and it is truly the best spreadsheet available. Excel lets you do things with formulas and macros (Visual Basic for Application) that are impossible with other spreadsheets. Similarly, Autodesk AutoCAD has been the best and suitable tool for creating digital drawings. Since most of the design engineers and surveyors are familiar with Excel and AutoCAD, I have prepared these tools on these application software platforms.

Although the above mentioned software are popular amongst all the engineers, it is a safe bet that less than two percent of users working in Afghanistan really understand how to get the most out of it. With the help of these tools, I have attempted to illustrate the fascinating features of Excel and AutoCAD and nudge you into that elite group.

I have noticed that there are fairly adequate number of books prepared for designing community led water supply systems. However, there are a few complete tools that are readily available for engineers to enhance their skills and capacities effectively and efficiently. Moreover, trainings and training materials distributed to design engineers in Afghanistan are not to a standard so that they are able to design the network systems comfortably. These tools are prepared aiming to fill this critical gap.

It would not have been possible for me to write this tools without the encouragement from United Nations Human Settlements Programmes (UNHABITAT, Afghanistan) and of course, Mr. Bijay Karmacharya, the Rural Programme Manager, UNHABITAT, Afghanistan. I would also like to thank all my colleagues working in the engineering divisions of UNHABITAT, Afghanistan for their tireless assistance and valued suggestions on composition and presentation.

What You Should Know

The Gravity Water Supply System Design Tools are prepared for practicing designers who have basic knowledge of discharge measurement and engineering surveying, technical calculation skills on water supply networks design and who are familiar with Excel and AutoCAD. I have attempted to elaborate these tools in such a way that the users will learn to use these tools quite comfortably. The calculations in the spreadsheets are intended to mimic manual calculations as far as possible. Stepwise manual calculations of typical examples are also presented in this manual.


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What You Should Have To make the best use of these tools, you need a copy of Microsoft Excel (XP or later, preferably 2003), Autodesk AutoCAD (2000 or later, preferably 2006) and Adobe Acrobat Reader (5.0 or later). The latest version of a free copy of Adobe Acrobat Reader can be downloaded from www.adobe.com. A downloaded copy of Adobe Acrobat Reader is included in the bundled CD-ROM.

The minimum system requirements for installing and running presented tools are:

Operating system : Windows 98/2000/NT/XP/Vista

CPU : 486/333MHz

RAM : 128MB

Display : 640 x 480 pixels, 256 colours

CD ROM : Double-speed (for installation only)

HD : 10 MB (approximately)

How These Tools Are Organized

There are many ways to organize the materials of these tools, but I settled on a scheme that divides them into three main parts.

Part I: Field Measurement and Design Spreadsheets

This part consists of twenty typical spreadsheets (ten calculations, four tables, five formats and a home page) covering all calculations and field formats related to gravity water supply design methods. These spreadsheets provide users to estimate measured discharges using conductivity meter, calculates heads by Abney / level surveying and to design project elements.

Part II: AutoCAD Drawings

This part consists of fourteen typical AutoCAD drawings in 2000 and 2006 versions covering drawings made for sources to end use water supply networks system. A single file with dynamic title blocks are used for each layout is used.

Part III: Users’ Manual

This manual (also in Adobe Acrobat PDF format) illustrates aspects of using the presented spreadsheets and stepwise calculations covering all illustrated methods for gravity water supply designs. Procedural guidelines for site investigation and engineering surveying are not covered in this manual. It is recommended that the manual on Discharge Measurement and Engineering Surveying should be referred to for these guidelines.

Part IV: Digital References and Archives

Digital copies of catalogue for pumps and pipes, National Solidarity Programme (NSP) Afghanistan technical manual on water supply and sanitation, etc are also enclosed in the CD-ROM.

http://www.adobe.com


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Download and Reach Out Electronic files included on the attached CD can also be downloaded from www.fukuoka.unhabitat.org . Preparation of these tools is a continuous process. I am always interested in getting feedback on them. Therefore, valuable suggestions and feedbacks are expected from all the stakeholders/users so that the overall quality of gravity water supply schemes is enhanced. Any suggestion and feedback can directly be sent to my email [email protected] or [email protected]. Sharing of related information regarding advanced options beyond these tools is also appreciated.

Pushpa Chitrakar

Engineering Advisor


http://www.fukuoka.unhabitat.org




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TABLE OF CONTENTS Page No.

NOTICE I

PREFACE II

ACKNOWLEDGEMENTS III

TABLE OF CONTENTS VI

1 INTRODUCTION 1

1.1 GENERAL 1

1.2 OBJECTIVES OF THE TOOLS 1

1.3 SOURCES OF THE TOOLS 1

1.4 TOOLS: SPREADSHEETS 2 1.4.1 Iterative Processes 3 1.4.2 Macro Security 4 1.4.3 Worksheet protection 5 1.4.4 User specific inputs 5 1.4.5 Errors 5 1.4.6 Cell notes 6 1.4.7 Cell Text Conventions 6 1.4.8 Pull Down menus and command buttons 7 1.4.9 Tools Menu and Toolbar 7

1.5 TOOLS: TYPICAL DRAWINGS 8

1.6 INSTALLATION 9

1.7 AUTOCAD PLOTTING 10

2 THE SYSTEM AND IMPLEMENTATION PHASES 13

2.1 INTRODUCTION 13

2.2 TYPES OF GRAVITY WATER SUPPLY SYSTEMS 14 2.2.1 System Type 01: Continuity of flow: Open or closed based on flows 14 2.2.2 System Type 02: Interconnected ends: Dead-end and other distribution system 14 2.2.3 System Type 03: Water sources: Ground water or surface water source 14

2.3 IMPLEMENTATION PHASES 16 2.3.1 Conception 16 2.3.2 Feasibility Study 16 2.3.3 Implementation 16 2.3.4 Operation, maintenance and Rehabilitation 17

3 FEASIBILITY STUDY 18

3.1 INTRODUCTION 18

3.2 DESK STUDY 18

3.3 FIELD STUDY: SITE INVESTIGATION 18


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3.3.1 Technical data collection 18 3.3.2 Non-technical Aspects (Social) 19

3.4 OFFIECE WORK: DETAILED DESIGN 19

4 WATER DEMAND 21

4.1 INTRODUCTION 21

4.2 DEMAND CALCULATIONS 22 4.2.1 Assumptions used for demand calculations 22 Example 4.1: Demand Calculations 22

5 INTAKE DESIGN 23

5.1 INTRODUCTION 23

5.2 DESIGN OF SURFACE INTAKES 23 Example 5.1: Surface Intake Sizing 24

5.3 INTAKE DESIGN PROGRAM BRIEFING & EXAMPLES 26

6 SEDIMENTATION TANK DESIGN 27

6.1 INTRODUCTION 27 Example 6.1: sedimentation Tank Design 27

6.2 GRAVITY FED RESERVOIR DESIGN PROGRAM BRIEFING & EXAMPLES 28

7 FILTRATION TANK DESIGN 30

7.1 INTRODUCTION 30

7.2 DESIGN OF SLOW SAND FILTER 31 Example 7.1: Design of Slow Sand Filter 32

7.3 DESIGN OF RAPID SAND FILTER 32 Example 7.2: Design of Rapid Sand Filter 33

7.4 GRAVITY FILTER DESIGN PROGRAM BRIEFING & EXAMPLES 33

8 RESERVOIR TANK DESIGN 35

8.1 INTRODUCTION 35

8.2 GRAVITY FED RESERVOIR TANK DESIGN 35

8.3 DESIGN PROCEDURES OF GRAVITY FED RESERVOIR TANKS 36 Example 8.1: Gravity Fed Reservoir Tank Design 36 8.3.1 Gravity Fed Reservoir design Program Briefing & Examples 37

8.4 DESIGN OF WELL FED RESERVOIR TANKS 38 Example 8.2: Well Fed Reservoir Tank Design 39 8.4.1 Well Fed Reservoir Design Program Briefing & Examples 42

9 PIPE NETWORK DESIGN 43

9.1 INTRODUCTION 43 Example 9.1: Natural Flow 46

9.2 SPECIAL CASES: CRITICAL HYDRAULIC CONDITIONS 47 9.2.1 Combination Pipes 47 Example 9.2: Combination Pipes 47


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9.2.2 Negative Pressure 48 Example 9.3: Negative Pressure 49 9.2.3 Air Locks: 50 Example 9.4: Air Lock 52

9.3 PIPE SELECTION IN AFGHANISTAN 54

9.4 A COMPLETE DESIGN 55 Example 9.5: Pipe Network Design 55

9.5 PIPE DESIGN PROGRAM BRIEFING & EXAMPLES 61

DATA SHEETS AND FORMATS 64

HDPE PIPE SPECIFICATIONS 64

HEAD LOSS FACTOR TABLES 64

WHO’S DRINKING WATER STANDARDS 1993 64

FORMATS 64

REFERENCES 81

TYPICAL DRAWINGS 83

LIST OF TABLES Table 1.1: Summary of Spreadsheets .................................................................................................. 2 Table 1.2: Summary of Drawings ......................................................................................................... 9 Table 4.1: Summary of Typical Daily Demands ................................................................................ 21 Table 5.1: Strainer Specifications...................................................................................................... 24 Table 7.1: Comparison of SSF and RSF ............................................................................................ 31 Table 8.1: A typical demand regime .................................................................................................. 35 Table 8.2: Summary of Reservoir Tank Calculations (all volumes are in m3) ................................. 37 Table 8.3: Summary of Reservoir Tank Calculations (all volumes are in m3) ................................. 40 Table 9.1: Recommended Values of C .............................................................................................. 45 Table 9.2: % Head loss for HDP Pipe (ISI Standard)......................................................................... 45 Table 9.3: Equivalent Pipe Lengths of Fittings ................................................................................. 46 Table 9.4: Flushing Velocities to prevent air locks .......................................................................... 51 Table 9.5: Design of Reservoir .......................................................................................................... 56


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LIST OF FIGURES Figure 1.1: Iterative process ................................................................................................................. 3 Figure 1.2: Activation of iteration in Excel 2003 (Tools => Option =>Calculations) .......................... 3 Figure 1.3: Activation of iteration in Excel 2007 (MS => Excel Option =>Formulas)......................... 4 Figure 1.4: Setting macros to medium security (Tools=> Macros=>Security) .................................. 4 Figure 1.5: Enabling macros ................................................................................................................. 4 Figure 1.6: Enabling macros in MS Excel 2007 (MS Office=>Excel Options=> Trust Centre=>Trust

Center Settings..=>Macro Settings). ............................................................................................. 5 Figure 1.7: Instruction incorporated in a cell note. ............................................................................. 6 Figure 1.8: A Formula presented in a cell note.................................................................................... 6 Figure 1.9: Colour coding of cell texts ................................................................................................. 6 Figure 1.10: Pull Down Menu ................................................................................................................ 7 Figure 1.11: Pull Down Menu ................................................................................................................ 7 Figure 1.12: Spreadsheet Menu and Toolbar ....................................................................................... 8 Figure 1.13: Computed AutoCAD commands in Excel ..................................................................... 10 Figure 1.14: Script file (4 sets of commands combined into a single file) and ACAD drawing ...... 11 Figure 1.14: Script file (4 sets of commands combined into a single file) and ACAD drawing ...... 12 Figure 2.1: Components of a typical gravity flow system utilizing surface water .......................... 15 Figure 2.2: Components of a typical gravity flow system utilizing underground water ................. 15 Figure 5.1: Typical Strainer Arrangement .......................................................................................... 24 Figure 5.2: Intake sizing spreadsheet “IntakeSizing” ....................................................................... 26 Figure 6.1: “SedimentationTank” spreadsheet ................................................................................. 29 Figure 7.1: Types of Filtration Methods ............................................................................................. 30 Figure 7.2: Components of a Gravity Filter System .......................................................................... 30 Figure 7.3: Sieve Graph of Typical Sand Sample .............................................................................. 31 Figure 7.4: Sedimentation Tank Sizing spreadsheet “SedimentationTank” ................................... 34 Figure 8.1: Gravity Fed Reservoir Sizing spreadsheet “ReservoirTank” ........................................ 38 Figure 8.2: Pump Performance Charts for H4K Italian Pumps ......................................................... 41 Figure 8.3: Well Fed Reservoir Sizing spreadsheet “ReservoirTankPump” ................................... 42 Figure 9.1: Longitudinal section and water profiles of a water supply system ............................... 44 Figure 9.2: Interpolation for % frictional factor for unlisted flow of 0.225 l/s. ................................. 45 Figure 9.3: Negative pressure along the pipe line ............................................................................. 49 Figure 9.4: Formation of a Partial Air Lock ........................................................................................ 50 Figure 9.5: Formation of a Total Air Lock .......................................................................................... 51 Figure 9.6: Prevention of Formation of Air Locks by analyzing pipe profiles ................................. 52 Figure 9.7: Diagram for Example 9.4 .................................................................................................. 52 Figure 9.8: Diagram for Example 8.5 .................................................................................................. 55 Figure 9.9: Intake and Sedimentation tank considered in Example 9.8 ........................................... 59 Figure 9.10: Pipe network design considered in Example 9.8 .......................................................... 60 Figure 9.11: Pipe Design as per Example 9.5 by Iranian Standard & Hazen Williams Method. ...... 62 Figure 9.12: Pipe Design as per Example 9.5 by Indian Standard & Tabulated Method. ................ 63


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1 INTRODUCTION

1.1 GENERAL

The presented set of tools is a complete set of Gravity Water Supply System Design Tools recommended for detailed designs of community water supply system projects in Afghanistan. It consists of MS Excel spreadsheets on surveying, data reduction and water supply design components, AutoCAD drawings on water supply networks components and this manual in Adobe Acrobat PDF formant.

The tools were prepared to provide a basis for design engineers to undertake field observations, data reduction and design water supply networks systems as per the standard requirements for preparing technical proposal in Afghanistan. Since most of the stakeholders are familiar with Microsoft Excel (XP or later) and AutoCAD (2000 or later) application software, the tools were prepared based on these software to make them simple and user friendly. During the preparation of these tools, special efforts were made so that the skills and knowledge of practicing surveyors and engineers are further enhanced by the use of these tools.

The tools consist of a set of twenty typical spreadsheets, fourteen drawings and a users’ manual. Most of the spreadsheets have been in used for about a year by water supply design engineers working under UN-HABITAT. Most of the drawings are prepared based on the illustrated design examples. Procedural guidelines, detailed step by step calculations and guidelines for using the presented spreadsheets are presented in the users’ manual. The Excel tools are prepared and distributed in template/read-only formats so that the original copies are always preserved even when users accidentally modify them.

1.2 OBJECTIVES OF THE TOOLS

The main objective of the presented tools is to enhance the quality of water supply system network designs both in rural and in urban Afghanistan. It is expected that the use of these tools helps fulfilling the main objective because:

1. They function as a set of “Time Saver Kit” for precision and speed (e.g. pipe network designs.).

2. They provide relevant references to design engineers for using and upgrading their skills and knowledge. Useful information is incorporated within the tools and this manual so that external references are minimized.

3. The depth of the study and design reports by different engineers are uniform and consistent and to the required depth.

4. They serve as templates so that there is a sufficient room for further creativity and improvement and tailoring to include specific needs of particular projects.

5. In addition, the tools are handy and user friendly. The user familiar MS Excel and AutoCAD software platforms have been used to develop them.

1.3 SOURCES OF THE TOOLS

The Tools were prepared aiming to enhance the overall quality of flow measurement, engineering surveying data and water supply system designs. Reviews of following sources were carried out during the preparation of the tools:


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1. Review and assessment of on-going and new technical projects and project proposals under National Solidarity Program (NSP) and Inter-communal Rural Development Project (IRDP) facilitated under UN-HABITAT, Afghanistan.

2. Feedbacks from all HABITAT engineers, NSP engineers and donors.

3. Experience from other similar technical projects within Afghanistan and abroad.

4. Standard textbooks, guidelines and other standards.

1.4 TOOLS: SPREADSHEETS

General as well as special features of Excel have been utilized while developing the presented spreadsheets. There are ten main spreadsheets each covering a tool. The list of the presented spreadsheets and their areas of coverage are presented in Table 1.1.

Table 1.1: Summary of Spreadsheets SN Spreadsheet Area of coverage

1 Home Home page for selecting spreadsheets and other links

2 Abney Use of Abney level surveying and plotting. Refer Discharge Measurement and Engineering Surveying tools for details. An electronic version of the manual is attached to the CD-ROM.

3 Levelling Levelling and plotting. Refer Discharge Measurement and Engineering Surveying tools for details.

4 Conductivity Computation of stream discharge by salt dilution method. Refer Discharge Measurement and Engineering Surveying tools for details.

6 IntakeSizing Chapter 5: Design of stream intake with fittings.

7 SedimentationTank Chapter 6: Design of sedimentation tanks.

5 ReservoirTank Chapters 4 & 8: Water demand calculations and design of reservoir tanks fed by gravity flows.

8 Filter Chapter 7: Design of slow and rapid sand filters.

9 ReservoirTankPump Chapters 4 & 8: Water demand calculations and design of reservoir tanks fed by pumping of wells.

10 PipeDesign Chapter 8: Design of pipe network systems using tabulated friction factors.

11 PipeDesignHW Chapter 8: Design of pipe network systems using analytical method by Hazen-Williams method.

12 GI Tabulated friction factors for Galvanized Iron (GI) pipes based on Indian Standards.

13 HDPE Tabulated friction factors for HDPE pipes based on Indian Standards.

14 HDPEHW Tabulated friction factors for HDPE pipes based on Hazen-Williams method.

15 HDPEData HDPE data sheet (diameters, thicknesses, pressure classes, PE types) manufactured by PolyPark (Iran)

16 AbneyCal Surveying and manual calculation format for Abney Level

17 CondCal Surveying and manual calculation format for Conductivity Method flow measurement

18 LevelCal Surveying and manual calculation format for Leveling.

19 StadiaBook Surveying and manual calculation format for Stadia method of surveying

20 GWSSCal Surveying and manual calculation format for pipe network design.


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To make to the best use of these spreadsheets, minimum knowledge of background information and main features of Microsoft Excel is mandatory. Although excel has many salient features, some of the basic features that were mostly used while preparing and using them are:

1.4.1 Iterative Processes

The spreadsheets are designed to save tedious and long iterative/repetitive calculations. Manual repetitive processes are the main source errors and are also time consuming factors. A typical repetitive process is presented in Figure 1.1.

Figure 1.1: Iterative process

As shown in the figure, the initial assumed value of X0 is amended until an acceptable error limit is reached. By default, this feature is disabled and generates Circular Reference Error. The iterative features in Excel can be activated by selecting Calculations tab (Tools->Options->Calculations>Tick Iteration (cycles & h)) and checking the iteration box. The Excel 2003 iteration dialogue box with this features activated is presented in Figure 1.2. Users of Excel 2007 have to activate iteration opening (MS Office =>Excel Options => Formulas) dialogue boxes and Tick Iteration (cycles & h)) and checking the iteration box (as presented in Figure 1.3).

Figure 1.2: Activation of iteration in Excel 2003 (Tools => Option =>Calculations)

EndY =f(X): X=f`(Y)

X=X+h

Is e=<|Yn+1 –Yn|

No

YesAssume Xo


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Figure 1.3: Activation of iteration in Excel 2007 (MS => Excel Option =>Formulas)

1.4.2 Macro Security

The spreadsheets contain Visual Basic for Application (VBA) functions and procedures. Because of the safety reasons against possible virus threats, MS Excel disables such VBA functions and procedures by default. Setting security level to medium (Tools => Macros => Security => Medium) and enabling the macros during the opening of the tools are required for the proper execution of the tools. Dialogue boxes for setting security level to medium and enabling the macros are presented in Figure 1.4 and 1.5.

Figure 1.4: Setting macros to medium security (Tools=> Macros=>Security)

Figure 1.5: Enabling macros


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Because of the high level of macro related risks, Excel 2007 has been designed to restrict many of the stand alone macros unless and until they are certified. Excel 2007 is rather complicated in terms of saving file formats and signing of macros to make them run properly. Therefore use of these tools shall be limited up to MS Excel 2003. In case these tools have to be used in Excel 2007 environment, procedures for enabling Macros in MS Excel 2007 are presented Figure 1.6.

Figure 1.6: Enabling macros in MS Excel 2007 (MS Office=>Excel Options=> Trust Centre=>Trust Center Settings..=>Macro Settings).

1.4.3 Worksheet protection

Most of the presented spreadsheets are protected against unwanted and accidental input which may result in wrong computational output. However, some of these spreadsheets are protected with a null password so that only expert Excel user can amend them based on their requirements.

1.4.4 User specific inputs

Some parameters such as the head loss overrated factor of 1.3 in the intake design have their standard optimum values. By default, the standard values are computed or presented. However, users are allowed to enter non-standard specific values under special circumstances.

1.4.5 Errors

Mainly three types of errors are known in the presented tools. One of them is the NAME# error which is caused by not executing custom functions and procedures because of the macro security level set to high or very high level. In case such an error occurs, close the workbook, activate the macro security level to medium and enable the macros when opening the workbook again. Calculation of friction factor by Hazen-Williams method (FrictionFactorHW (Q, Pipe PN or GI, Diameter, Thickness)) is a typical NAME# error in the traverse spreadsheets.


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Malfunctioning of circular references or mathematical errors generates VALUE# error or unexpected results (such as negative millions cubic meters of water in the reservoir tanks). When such an error occurs, select the error cell a cell note of the spreadsheets, press F2 and press Enter. Such errors can also be automatically corrected by inputting the required input values.

A REF# error occurs due to the deletion of unnecessary rows or cells, for example in pipe design spreadsheet. In such an instance, copy the second cell from the second computation line of any branch or use original workbook template.

1.4.6 Cell notes

Cell notes are comments attached to cells. They are useful for providing information related to computational procedures. Adequate cell notes are provided in the presented spreadsheets so that external references are minimized. For example, a cell note for properly inputting vertical angles in Abney Level spreadsheet is presented in Figure 1.7.

Figure 1.7: Instruction incorporated in a cell note.

Similarly, the cell note presented in Figure 1.8 presents a formula for calculating the length of small diameter of the combined pipes.

Figure 1.8: A Formula presented in a cell note

1.4.7 Cell Text Conventions

Three different colour codes are used to distinguish three different cell categories. A typical example of colour coding of cells is presented in Figure 1.9. The colours and categories of these cells are:

Blue cells: These cells represent mandatory input cells. These cells are project dependant cells and project related actual inputs are expected in these cells for correct outputs. The mandatory inputs include the name of project, coordinates, station elevations, measured pipe lengths at site, etc.

Figure 1.9: Colour coding of cell texts


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Red cells: These cells are optional input cells. Standard values are presented in these cells. Values in this type of cells can be amended provided that there are adequate grounds to do so. It is worth noting that care should be taken while changing these values. As presented in the example, the recommended factored length (Pipe L Factor) of 10% is specified. 10% added length is justifiable to cater for neglected turbulent losses. Moreover, the additional lengths are also recommended for purchasing to cater for unaccounted undulated pipe laying and spare pipes required for repair and maintenance. This cell can be changed to 1.05 or 1.0 if these factors are already considered during surveying.

Black cells: The black cells represent information and or output of the computations. For the sake of protecting accidental and deliberate amendment or change leading to wrong outputs, most of these cells are protected from editing. It is recommended that care should be taken when amending black cells.

1.4.8 Pull Down menus and command buttons

Some input cells are equipped with pull down menus to facilitate the users to input standard values related to input cells. Cells related to pull down menus can have any user specific values than the stated standard values if the data cells are not of mandatory type. In Figure 1.10, the pull down menu for angular measurement type is activated. There are two types of angular measurements, namely, Degrees and Gradians that can be input. This input is a mandatory type and users can not enter any values other than the specified ones. “Degrees” option is selected as an input.

The outcome of the computation will be erroneous if the mandatory input data does not match with the desired predefined values. Therefore, the spreadsheets are designed to reject such invalid values and flag error messages with suggestions. As demonstrated in Figure 1.11, an error is flagged when Radians is entered in stead of Degrees or Gradians.

Figure 1.10: Pull Down Menu Figure 1.11: Pull Down Menu

1.4.9 Tools Menu and Toolbar

A menu and a toolbar are added to the workbook to facilitate users’ access to all the tools including accessing online manual and sending feedbacks. They are set to active only when the workbook is active. The toolbar has to be dragged to either on top or side of the screen (as presented in Figure 1.12) for convenience.


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Figure 1.12: Spreadsheet Menu and Toolbar

1.5 TOOLS: TYPICAL DRAWINGS

As stated earlier, an AutoCAD drawing file with fourteen layouts for typical elements were prepared and incorporated in the tools. These drawings covering from intake to tap-stands are presented at the end of this manual. Since they are only typical drawings, additions of drawings and the level of details may be changed to fulfil specific needs of a particular project. The level of consistency, compatibility and the extent of information in the drawings are complete and appropriate for community led gravity water supply systems. The main features of the presented drawings are:

1. These drawings are recommended only for community led gravity water supply systems.

2. Minimum required details such as plans and adequate cross sections are provided.

3. Recommended values of elements such as the minimum thickness of a stone masonry wall, longitudinal slope of a sedimentation tank, etc, are presented in the drawings.

4. Standard line types and symbols are used.

5. Basic drawing elements such as a dynamic title box with adequate information and controlling signatories, scales, etc, are presented.

6. All drawings with standard layouts for printing are presented.


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The dimensions and geometries of the presented drawings should be amended according to the considered projects details. These drawings are listed in Table 1.2. Table 1.2: Summary of Drawings SN Drawing Area of coverage/ Remarks

1 General Layout Plan: General layout of a scheme utilizing stream intake.

2 Headworks General Layout Plan: General layout of a headworks with a weir, a sedimentation tank and a slow sand filter.

3 Weir Plan and Sections: Weir with dimensions and alternative weir types.

4 Sedimentation Tank Plans and Sections: Detailed dimensions and an alternative tank.

6 Slow Sand Filter Tank Plans and Sections: Detailed dimensions and an alternative tank.

7 50m3 Reservoir Tank Plan, Section and Details: Reservoir ground tank.

5 25m3 Reservoir Tank Plan, Sections: Tanks resting on an RC frame.

8 25m3 Reservoir Tank Reinforcement Details

9 Pipe Networks System Pipe Design: Output diagram of a pipe system design.

10 Pipe Networks System Profile: A longitudinal profile of a leg of a pipe system design.

11 Miscellaneous Details Manhole, Tap-stand and Pipe Laying

12 Break Pressure Tank With and Without Float Valves

13 Spring Intake Plan and Section

14 Stream Intake with in-built Filter Plan and Sections

1.6 INSTALLATION

It is recommended to install the Tools under “C:\Design Aids\Gravity Water Supply\” directory for the full functionality of these tools. In case it is installed elsewhere, the external links for online manual will not work. It is also recommended that the working copy of project specific spreadsheet to be saved under the installation directory.

As stated earlier, these tools are basically design for MS Excel 2003 although they also run under MS Excel 2000 or 2007. In order to run the spreadsheet properly, some version of MS Excel 2003 may have to be updated by running the supplied patch file “Office2003SP2-KB887616-FullFile-ENU.exe”. In case the macros still are not running properly, uninstall the office completely and delete the related subdirectories. Reinstall the Excel and run the patch file. Set the security level to medium before opening the spreadsheet.

Some Excel 2003 used in Afghanistan have problems running macros properly. Follow the installation procedures as

1. Uninstall all Excels.

2. Install MS Excel 2007.

3. Install MS Excel 2003.

4. Run the patch file.


10

1.7 AUTOCAD PLOTTING

Abney, levelling and pipe design worksheets are equipped with the collection of script file output commands that help plotting surveying features in to Autodesk AutoCAD. A scrip file is a collection of text commands used in AutoCAD environment. A script can execute any command at the Command prompt except a command that displays a dialogue box. A scrip file is a text file and has a collection of these commands. These commands should be copied and pasted on a Notepad and saved as text file with .scr extension.

These script files can be run in AutoCAD environment by inputting script files by inputing SCR or SCRIPT on command line. Inputting the specific file plots AutoCAD objects.

An example of computed AutoCAD commands for plotting longitudinal profile of pipe is presented in Figure 1.13. The corresponding script file ready for plotting corresponding pline, points and station names with residual heads is presented in Figure 1.14. Finally, the plotted ACAD drawing is presented in Figure 1.15. It is worth noting that care should be taken to provide accurate number of spaces while running all these command sets in a single file.

AutoCad TEXTSIZE 1.5 PDSIZE .5 PDMODE 2 Ground HGL

pline pline point Stations

0.001,2666.775 0.001,2666.775 0.001,2666.775 text 0.001,2666.775 1 45 SRC1-RH: 0.001

179.817,2650.493179.817,2665.26 179.817,2650.493 text 179.817,2650.493 1 45 Combination 1-RH: 7.384

2199.614,2576.9432199.614,2611.7062199.614,2576.943 text 2199.614,2576.943 1 45 RVT1-RH: 9.998

2526.693,2415.7732526.693,2515.3322526.693,2415.773 text 2526.693,2415.773 1 45 JCT1-RH: 32.398

2718.058,2261.9232718.058,2409.0072718.058,2261.923 text 2718.058,2261.923 1 45 JCT2-RH: 23.763

2962.238,2101.8932962.238,2293.6252962.238,2101.893 text 2962.238,2101.893 1 45 JCT3-RH: 22.324

3059.008,1937.0233059.008,2175.8673059.008,1937.023 text 3059.008,1937.023 1 45 JCT4-RH: 23.556

3451.706,1774.8133451.706,2052.4533451.706,1774.813 text 3451.706,1774.813 1 45 JCT5-RH: 19.398

3765.192,1606.6633765.192,1922.6493765.192,1606.663 text 3765.192,1606.663 1 45 JCT6-RH: 19.173

3982.834,1463.4833982.834,1789.1953982.834,1463.483 text 3982.834,1463.483 1 45 Combination 2-RH: 4.863

4738.592,1233.6134738.592,1590.0144738.592,1233.613 text 4738.592,1233.613 1 45 TAP07-RH: 15.345 Figure 1.13: Computed AutoCAD commands in Excel


11

Figure 1.14: Script file (4 sets of commands combined into a single file)


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SRC1-R

H: 0.00

1

Com

binati

on 1-

RH: 7.38

4

RVT1

-RH: 9

.998

JCT1

-RH: 3

2.398

JCT2

-RH: 2

3.763

JCT3

-RH: 2

2.324

JCT4

-RH: 2

3.556

JCT5-R

H: 19.3

98

JCT6

-RH: 1

9.173

Com

binati

on 2-

RH: 4.86

3

TAP07

-RH: 1

5.345

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

Figure 1.15: ACAD drawing produced by the script file (line colour and font size amended)


13

2 THE SYSTEM AND IMPLEMENTATION PHASES

2.1 INTRODUCTION

A Gravity Water Supply System (GWSS) consists of a system of pipe networks and other elements conveying safe and assured quantity of water from a source to users’ points by the action of gravity. The system mostly consists of:

• Intakes (springs, stream, Kharezes and wells)

• Tanks (collection, sedimentation, break pressure, distribution and reservoir tanks)

• Outlet (taps, sediment outlets, pressure release outlets)

• HDPE or GI pipe networks connecting above structures.

A typical system of a gravity water supply system consists of four technical components / functions as:

1. Production: This component consists of collecting water from the continuous source. Depending on the source of water it can be further sub-divided into following categories:

a. Underground intake: Underground intakes such as production wells and Kharezes are used as water sources in a system where ground water is utilized as the sources of water. Most of the water supply systems in Afghanistan utilize production wells as the sources of water. The quality of such ground water is less contaminated, has less suspended particles and is constant in supply. Costs of production wells are usually high.

b. Spring intake: A spring occurs when an underground aquifer penetrate the ground surface by means of gravity or hydrostatic pressure. The quality of water from springs is usually better than underground and surface sources. Fewer structures are required for spring intakes making their initial as well as operational costs lesser than the other types of production components. However, continuity of such a spring should be confirmed before deciding other design parameters.

c. Surface intake: It consists of collecting water from surface water bodies such as rivers, streams, etc. Quality of water from such intakes is generally highly contaminated with relatively higher rate of suspended sediments. These intakes have large fluctuation of water quantity and are susceptible to large floods.

2. Transmission: A transmission component of a water supply system conveys water from production unit to a storage reservoir. A pump drives water to a reservoir tank in case of production well system. On the other hand gravity force is utilized in case of gravity water system consisting of surface water intakes. Provision of purification of water (bacteria, sediment, etc) is generally made before transmitting water to a reservoir.

3. Storage: Water demand over a period of time is not constant but fluctuates considerably. Provision of storage tanks helps storing water when the demand is less and supplying the stored water when the demand is high. These tanks are generally designed to balance incoming and outgoing flows for a period of 24 hours.

4. Distribution: It conveys water from storage tank to distribution outlets (service connections) where beneficiaries consume water.


14

Pipe networks in transmission and distribution systems may have some additional components such as chlorination tanks, sedimentation tanks, pressure tanks, distribution tanks, air release valves, sediment flushing outlets, etc.

2.2 TYPES OF GRAVITY WATER SUPPLY SYSTEMS

2.2.1 System Type 01: Continuity of flow: Open or closed based on flows

In case a continuous water yield (supply) is adequate to meet the continuous demand at any time, an open system is implemented for supplying water to the distribution points without providing any storage provision. A continuous water flow with or without faucets (taps) are used in this kind of system. This system is optimum where the distance between source and supply is relatively short.

In reality, the distance between surface intakes and the distribution points is mostly long and the yield is less than the maximum continuous demand. In such an instance, a closed system with reservoirs is optimum and hence is used.

2.2.2 System Type 02: Interconnected ends: Dead-end and other distribution system

Based on distribution networks systems, water supply systems can be defined as:

1. Dead-end /Tree System: In this system a number of sub-main pipes are laid perpendicular to a main distribution pipe. Each of these sub-mains is sub-divided into several branches and laterals. Service connections are given from these laterals. This system is mostly used in Afghanistan. The presented pipe networks design tools are based on this system. A typical diagram of this type of system is presented in Figure 9.8.

2. Other systems: Other advanced systems such as Grid-iron system, Ring system and Radial systems are used in modern planned cities. Sub main pipes are interconnected in these systems.

2.2.3 System Type 03: Water sources: Ground water or surface water source

Based on the utilized sources of water, gravity water supply systems can be defined as:

1. Gravity water supply system utilizing underground water source: This system utilizes water stored in underground aquifers. Water is pumped up to an elevated reservoir and distributed through main, sub-main and laterals. This system is used in most of Afghanistan water supply systems.

2. Gravity water supply system utilizing surface water: In case adequate amount of potable surface water is available at adequate height, gravity water supply system utilizing gravitational force is used for conveying water from one location to the other. This system is mostly used in mountainous regions of Afghanistan like Bamyan and Badakshan.

The basic differences between these systems are the source of water and use of reservoir tank at different heights. In pumped system, elevated tanks are generally used at heights where the head of water can drive water to distribution systems by gravitational force. Reservoir tanks are generally used on the ground in the second type of systems. Gravity Water Supply System Design Tools are capable of designing both the systems.


15

Tap

TapTap

Tap

TapTap

Tap

Stream

Intake

Sedimentation tank

Break pressure tank

Reservoir tank

Figure 2.1: Components of a typical gravity flow system utilizing surface water

ElevatedReservoir Tank

Pump House withvalve boxes

Well with Submersible pump

Tap

Tap Tap

Tap

Tap

Tap

Distribution line

Figure 2.2: Components of a typical gravity flow system utilizing underground water


16

2.3 IMPLEMENTATION PHASES

A water supply system has to pass through different phases from conception to operation. A brief description of each phase is presented in the subsequent sections.

2.3.1 Conception

Need of a water supply projects, conceptual project layouts and financing are determined during the conception phase. In Afghan rural areas, social mobilization is carried out in order to determine water supply projects as priority projects. If water supply project is chosen as a priority project, it will be recommended for further actions such as feasibility study and implementation.

2.3.2 Feasibility Study

In general a pre-feasibility study is carried out prior to conducting a full fledged feasibility study. Because of the limited resources, both the pre and feasibility studies are combined in Afghan community water supply system designs. A feasibility study is conducted to check technical robustness and financial feasibility of the project. Following activities are conducted during the feasibility study of a gravity water supply system:

1. Desk Study:

a. Request from implementing authorities (CDCs, NSP, etc)

b. Fund allocation and preliminary reviews

c. Community consultation: overview, resources and water right issues, community willingness, demand, household, population, local contribution, etc.

2. Field Study: Activities such as briefing and community consultation, verification of collected data during the desk study, discharge measurement, engineering surveying, issues related to water rights and tentative layout are conducted during the field study.

3. Office Work: Activities such as data reduction, fixing layout, detailed design, quantity and cost estimates, feasibility statement and implementation schedule should be carried out during office works. A project report should be prepared at the end of the feasibility study.

2.3.3 Implementation

Following activities should be carried out during implementation phase of a gravity water supply system:

1. Securing of fund and implementation modality.

2. Disbursement schedule.

3. Formation of implementation committees (technical, procurement, monitoring and evaluation) and implementation.

4. Contract preparation and awarding.

5. Training of operators (on-the-job and separate).

6. Operation manual (including repair, maintenance) and business plan preparation/update.


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2.3.4 Operation, maintenance and Rehabilitation

Following activities should be carried out during operational phase of a gravity water supply system:

1. Implementation of business plan.

2. Tariff update from time to time (usually annually)

3. Maintenance and

4. Future extension and expansion plan.


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3 FEASIBILITY STUDY

3.1 INTRODUCTION

The main purpose of a feasibility study of a community led gravity water supply project is to prepare a feasibility study report. It should clearly mention whether the project is feasible. The study report should be of adequate depth so that prospectus contractor can understand the project and can quote costs required for the project implementation. As mentioned in the preceding chapter, a feasibility study consists of following three steps:

1. Desk Study

2. Site Investigation

3. Office Works

3.2 DESK STUDY

The main purpose of a desk study is to prepare and plan for the upcoming site investigation and office works. The desk study consists of:

1. Confirm CDC’s finalization of the selection of GWSS project as their priority project.

2. Fund allocation and preliminary review of tentative costs.

3. Community communication regarding:

o Overview of the project including security condition.

o Local resources inventory (materials and manpower)

o Households and population of targeted beneficiaries

o Total demand

o Local contribution (in kind and in cash)

o Possible sources and location of water

o Project layout and routes.

4. Planning for feasibility study activities at site

5. Prepare a check list of items required (including cash requirement).

3.3 FIELD STUDY: SITE INVESTIGATION

Site investigation consists of collecting technical as well as social data and verification of data collected during the desk study. Adequate social mobilization should be carried out before and after technical data collection. The activities under the site investigation are outlined as:

3.3.1 Technical data collection 1. Population study:

o Number of beneficiary households.

o Present population and growth including inflow due to internally displaced people and migration.

o Demand assessment.

2. Hydrological study


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o Locations of potential sources.

o Yield: flow measurement in dry/lean season (bucket, conductivity method or visual if the source is abundant) for surface water source. Local well yield near the proposed location in case of underground source usage.

o Quality of water at the potential sources by visual inspection and testing if clean. Water with calcium (white scaling/deposition when boiled) is widespread in Afghanistan. As far as possible, such water should be avoided to prevent scaling of the system making the system technically less efficient and hazardous health-wise.

3. Topographical study:

o General visibility from source to the villages to be noted. Reconnaissance and GPS surveying before commencing the final topographical surveying.

o Preparation of general layout locating main project structures and benchmarks.

o Location of supply points (households, social institutions like schools, hospitals, offices, mosques, etc). According to NSP guidelines for rural water supply system, one tap should be provided for maximum of 25 households.

4. Logistical study

o Means of transportation.

o Distances to road heads / airports.

o Availability of materials

o Availability of local skilled and unskilled manpower.

o Unit rates of local human resources and materials.

5. Geological study

o Visual inspection of type of soil along the pipe routes and at major structure locations.

o Possible geological problems and solutions.

o Location of crossings.

o Locations of landslides.

3.3.2 Non-technical Aspects (Social) 1. Water source utilization and potential disputes

2. Land rights of project locations

3. Possible political/ethnic divisions.

4. Economic conditions of village

5. Priority that the villagers place on water.

6. Expectation of the community

7. Abilities of community leaders and decision makers.

8. Condition of prior development projects

9. Community’s current sanitation practices.

3.4 OFFIECE WORK: DETAILED DESIGN 1. Data reduction: The technical data collected from site should be reduced. Plotting of plans

and profiles showing the potential project location should be carried out. Measured discharges should also be calculated. A tentative project layout should be prepared.


20

2. Detailed Design: Detailed design of project components, quantity and cost estimates should be carried out to check if the project is financially affordable and technically sound.

3. Report Preparation: Preparation of final drawings and report with feasibility statement, findings and recommendations.

4. Report submission: Submission of report to concerned authorities and follow up.


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4 WATER DEMAND

4.1 INTRODUCTION

Water demand calculation is a process of assessing required volume of water of a targeted future population of a community. It includes registration of present population data (families, households and locations), assessing personal and institutional daily water needs, assessing typical population growth and estimating future (typically 10-20 years of time) demands.

Water demands for regular village/city residents, students (day-scholar and boarding), mosques, hospitals and health posts, government offices and institutions, public utilities (public bath, street washing, etc) should be calculation using existing or standard demands. A summary of typical demand patterns is presented in Table 4.1.

Table 4.1: Summary of Typical Daily Demands Consumer Standard

(l/c/d) Range (l/c/d)

Remarks

Villagers 45 25 to 45 Students (day-scholar). 10 5 to 10 Students (boarding) 65 35-65 Mosques 3.6 (Assuming 60% go to mosques two times a

day using 3 litres of water per visit). 1000 litres for a mosque with 300 villagers.

Hospitals & health posts with beds

500-1000 liters/bed

Health clinic without beds

1000 - 2500

Rural health clinics

Government offices and other institutions

500 to 1000

Rural offices up to 20 staff.

Water use pattern of a specific location is usually different than the others. Factors affecting water use patterns are:

• Local climate and seasons (more water in hot season)

• Culture/Religion (Afghan people get up relatively earlier than others)

• Degree of civilization (villagers get up earlier but utilize less water than urban dwellers)

• Industrialization (more water for industrialized communities)

• Economic status and affordability (more water for rich people)

• Education on conservation (waste of water due to lack of conservation awareness)


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4.2 DEMAND CALCULATIONS

4.2.1 Assumptions used for demand calculations

1. Population growth rate (i) = 3% (prudent rate for Afghanistan)

2. Design Span (n) = 10 to 20 years (standard is 20 years)

3. Population at the end of nth year (Pn) = Po (1+i)n. Where Po is the present population.

4. Total daily demand for regular residents (D) = d * Pn. Where d is total daily demand per capita in l/s.

5. Total demand = total individual demand + other demands such as schools, mosques, etc.

Example 4.1: Demand Calculations

Calculate total water demand for a village called Khawal in Bamyan with:

• Number of families (HH) = 220

• Average persons per family (ph)= 6

• Design span (n) = 20 years

• Population growth rate (i) = 3%

There is a day-scholar school with 400 students and a mosque. Assume that the demands for these institutions are additional although the students and mosque goers are from the same village. Use standard demand for regular villagers and use 50% of standard demands for mosques and schools.

Present population = number of households x average persons per HH

Or, Po = HH x ph

= 220 x 6 = 1320 persons

Population at the end of 20th year = present population (1+growth rate) design span

Or, Pn = Po (1+i) n

= 1320(1+3/100)20 = 2384 persons

Assume standard daily per capita demands 45 litres for villagers, 10 litres for students and 3.6 litres for mosque goers.

Total daily demand = number of users x daily rates (for villagers, schools and mosque)

= 45 x 2384 + 50%x10x400(1+3/100)20 + 50% x 3.6x2384

= 115,183 litres per day

= 115.183 m3 per day


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5 INTAKE DESIGN

5.1 INTRODUCTION

Depending on the type of water sources, following types of intakes are used for supplying potable water to the systems:

1. Production well: Shallow as well as deep production wells are used for collecting water in Afghanistan. Deep wells are widely used as water intakes in most of the Afghanistan community managed piped water supply systems. Since there is a complete lack of underground hydrological data in most of these areas, most of wells in these projects are designed based on limited existing data of nearby wells. The operation patterns of these wells are amended based on the actual yields. Design of wells is beyond the scope of this document and therefore not elaborated here.

2. Surface Intake: Stream and spring intakes are the two most popular surface intakes for withdrawing required quantity of water. An ideal surface intake should fulfil following criteria:

a. Withdrawal of desired flow (quantity and quality)

b. Sediment bypass of diversion structure

c. Debris bypass

d. Hazard flow bypass

e. Sediment control at the intake

f. Settling basin control (settling of sediment, flushing, etc)

g. Safe Structure (safe against sliding, overturning and sinking)

5.2 DESIGN OF SURFACE INTAKES

Design of surface intakes consists of calculating driving head which conveys designed flow from the proposed intake to a downstream sedimentation or collection tank. The driving head is the cumulative summation of frictional and turbulent head losses from intake to the considered free downstream surface. It is recommended that the calculated total head loss should be overrated by at least 30% as:

Head loss HL = over rated factor of 1.3*(frictional head loss + turbulent head loss)

HL = 1.3*(HLf + HLt)

Generally, pipe friction losses for community led water supply system are calculated using Hazen-Williams as:

Q = 0.2785*C*D2.63*S0.54

Where, Q = discharge (m3/s) C = Hazen-Williams friction coefficient (typically, 140 for HDPE and 100 for GI), the recommended values of C are given in Table 9.1. D = internal diameter of pipe (m)


24

S = Hydraulic gradient (energy slope) = 1: N = HL/L L = total length of the pipe (m)

The frictional loss per 100m of pipe length (% frictional loss, %HLf) can be calculated as:

%HLf = (Q/(0.2785*C*D^2.63))^(1/0.54)*100

Turbulent head losses are the summation of head losses at entrance, bends and exits and at every change of velocity along the pipe and can be expressed as:

HLt = ∑ K * v2/2g

Where,

K = turbulent coefficient (inlet = 0.5,outlet = 1.0, etc)

v = pipe velocity (m/s) = Q/Area of pipe = 4*Q/(π*D2)

Pipe head losses due to friction and turbulent are further described in detailed in Chapter 9.

In order to trap unwanted sediment and debris at intake, strainers are used upstream end of the intake pipe. A strainer used in water supply project is a perforated pipe (HDPE or GI) with standard holes usually at 10mm c/c for collecting water. Adequate number of holes arranged in rows and columns around the periphery of pipes have to be used for assured quantity of water withdrawal. Typical HDPE strainer specifications (diameter of holes and number of holes) for the stated pipes and flows are given in Table 5.1.

Figure 5.1: Typical Strainer Arrangement Table 5.1: Strainer Specifications Outlet pipe diameter (mm) =>

16 20 25 32 40 50 63

Flow (l/s) 0.2 0.45 0.8 1.25 1.8 3 20 5 HDP Reducer 32/20 40/25 50/32 63/40 63/50 90/63 90/75 3.5mm dia, holes 48 100 168 255 375 651 1008 4mm dia, holes 40 80 132 195 285 504 777 5mm dia, holes 21 54 88 140 196 323 494 6mm dia, holes 21 32 60 91 130 234 342 7mm dia, holes 12 24 50 72 96 170 255

A factor of safety of 2 is recommended for calculating the number of perforated holes.

Example 5.1: Surface Intake Sizing

Calculate the driving head of a water supply surface intake for considering inputs:

• Design flow (l/s) = 0.6

Perforated HDPE Strainer

Perforated end capHDPE Reducer

Flow


25

• Outlet pipe, D (mm) = 25.4

• Outlet pipe type = GI

• Pipe length d/s open surface, L (m) = 5.00

• Strainer hole size, d (mm) = 3.50

• c/c distance of strainer holes (mm) = 10

• Over rated factor for head loss (safety) = 1.3

• Take the summation of K for an inlet, an outlet and a 45 degree bend as 2.0

Strainer Calculation:

As per Table 5.1, the number of holes for 25mm diameter pipe with 3.5mm holes is 168 (holes for 0.8 l/s flow is selected). The diameter of perforated pipe (Dp) is 50mm.

With a safety factor of 2, the total number of perforated holes is Nd = 2 * 168 = 336.

The number of rows along the pipe for 10mm c/c distance holes, Nrow = INT (π*D/10)

Nrow = INT (π*D/10) = INT(π*50/10) = 15

The number of columns Ncol= Nd/Nrow = 336/15 = 22.4 say 25

Minimum length of the strainer Ls= Ncol * c/c distance = 25*10 = 250mm

Driving Head Calculations:

Headloss factor for 25.4mm diameter GI pipe with C = 100 is

%HLf = (Q/(0.2785*C*D^2.63))^(1/0.54)*100

= ((0.6/1000)/(0.2785*100*(25.4/1000)^2.63))^(1/0.54)*100

= 13.3986736m per 100m

Frictional headloss for 5m long pipe HLf = %HLf * 5/100

= 13.3986736* 5/100

= 0.6699m

Turbulent headloss HLt = ∑ K * v2/2g,

where v = 4*Q/(π*D2)

= 4*0.6/1000/(π*(25.4/1000)2)

= 1.184 m/s

Therefore, HLt = 2 * 1.184^2/(2*9.81)

= 0.1435m


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Total driving headloss HL = 1.3(HLf + HLt)

= 1.3*(0.6699 + 0.1435)

= 1.057m

5.3 INTAKE DESIGN PROGRAM BRIEFING & EXAMPLES

The manual calculations considered in Example 5.1 are taken as inputs for a typical example for calculating the same parameters in the presented spreadsheet called “IntakeSizing”. The final outcome of the spreadsheet is the calculation of the driving heads based on the frictional and turbulent head losses.

Date 22-May-2008 Revision 2006.05Spreadsheet Developed by: Mr. Pushpa Chitrakar, Engineering Advisor, UNHABITAT, Afghanistan.Project Khawal CWSS Surveyed by:Location Bamyan Centre Checked by: CDC/CCDC Khawal CDC

Design flow (l/s) 0.600 10Outlet pipe,D (mm) 25.4 50Outlet pipe type GI 336Pipe length d/s open surface, L (m) 5.00 15Strainer hole size (d) 3.50 25c/c distance of stainer holes (mm) 10 250Hazen William coefficient (C) 100 13.399Wall thickness, t (mm) 1.18Over rated factor for headloss (safety) 1.3 1.057Turbulent Coeff. K 2.00

Diameter of HDP Strainer pipe (mm)c/c distance of strainer holes (mm)

Strainer pipe length (mm)

Driving head, dh (m)

Skin friction factor %Velocity, v (m/s): Ok

Nr of holes per rowNr of rowsNr of strainer holes

Intake sizing (Pipe Design by Hazen-Williams)United Nations Human Settlements Programme (UN-HABITAT), Afghanistan

Figure 5.2: Intake sizing spreadsheet “IntakeSizing”


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6 SEDIMENTATION TANK DESIGN

6.1 INTRODUCTION

In a water supply system, a sedimentation tank is used for settling and trapping of suspended sediment. This is achieved by reducing flow velocity and turbulence the passing flow. The velocity is reduced by providing relatively a bigger section where as the turbulent is reduced by providing smooth and less turbulent straight and transitional sections. Following criteria are recommended while designing a sedimentation tank:

1. Settling of suspended sediment by reducing the flow velocity.

2. Desired water depth of the basin (D) = 750-1000mm

3. Minimum aspect ratio (L/W) = 4 (length over width ratio)

4. Detention time t = 900-1200 sec with storage reservoir

= 3600 sec without storage reservoir

Dimensions of a sediment tank are calculated by using following expressions:

Velocity v, (m/s) = Flow/Cross sectional area (Q/A)

Tank Capacity C, (m3) = t * Q

Length of tank = C/A

Example 6.1: sedimentation Tank Design

Calculate the size of a reservoir tank considering following inputs:

• Design flow, Q = 1.5 (l/s)= 0.0015 (m3/s)

• Water Depth, D (m) = 1.00

• Water Width, W (m) = 0.75

• No reservoir (detention time t = 3600 seconds)

Safe yield:

To avoid turbulence, velocity should not be more than 0.05m/s.

v = Q/(W*D)

= 0.0015 /(1.00 * 0.75)

= 0.002 m/s, which is less than 0.05 m/s, hence okay

Tank capacity (C) = t*Q

= 3600 *0.0015

= 5.4 m3


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Length of tank L = C/(W*D)

= 5.4 /(1.00 * 0.75)

= 7.20m

Aspect Ratio, L/B = 7.2/1.0 = 7.2 > 4, hence Ok.

A typical sedimentation tank suitable for smaller schemes is presented in Figure 6.1. A single control box is adequate for controlling inlet and outlet. In case space along the length is not a problem, a 7.2m long sedimentation tank without any bend should be provided. Separate controls boxes for inlet and outlet should be provided in such a case.

6.2 GRAVITY FED RESERVOIR DESIGN PROGRAM BRIEFING & EXAMPLES

The manual calculations presented in Example 6.1 are taken as a typical example for calculating the same parameters of sedimentation tank design presented in a spreadsheet called “SedimentationTank”. A sketch is also included in the design.


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Date 16-Jun-2008 Revision 2006.05Spreadsheet Developed by: Mr. Pushpa Chitrakar, Engineering Advisor, UNHABITAT, Afghanistan.Project Sayed Baba MHP Surveyed by:Location Saighan, Bamyan Checked by: CDC/CCDC Sayed Baba MHP

Design flow (l/s) 1.5 0.00200Water Depth (m) 0.75 5.400Water Width (m) 1.00 7.200

Detention time, t (sec) 3600 7.200

325

100

100

Sedimentation Tank SizingUnited Nations Human Settlements Programme (UN-HABITAT), Afghanistan

Velocity, v (m/s): OkTank capacity, V (m3)Length, L (m)Aspect Ratio, L/B, (m): Ok

Figure 6.1: “SedimentationTank” spreadsheet


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7 FILTRATION TANK DESIGN

7.1 INTRODUCTION

Water may be contaminated with suspended particles, bacteria and other soluble materials and may pose threats to human health. Sedimentation tank are used to trap relatively bigger sediments. On the other hand a filter is used for removing finer particles, bacteria, colour and odour of water so that the water is potable as well as palatable. In filtration, water is passed through a set of layers of granular materials like sand and gravels. As presented in Figure 7.1, the filtration method can be categorised as gravity and pressure filtration methods. The gravity filter can further be divided into slow sand filter (SSF) and rapid sand filter (RSF). Filtrations methods using filtration tanks, mainly SSF, are used in only a small fraction of community water supply network systems.

Figure 7.1: Types of Filtration Methods

Both the gravity filters work on the same principle of allowing water to enter the filter media with the help of the gravitational force. The outputs and efficiencies differ mainly because of different media geometries and dimensions and driving head. As presented in Figure 7.2, both the systems contain housing, water layer, filter bed, drainage system and flow control components. A comparative table of SSF and RSF is presented in Table 7.1.

Overflow

Treated Water

Control Valve

Backflow ofwater for cleaning

Raw water input

Water layer

Sand layer

Gravel layer

Under Drainage

Housing

Collection tank

Figure 7.2: Components of a Gravity Filter System


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Table 7.1: Comparison of SSF and RSF Particulars Slow Sand Filter (SSF) Rapid Sand Filter (RSF)Rate of filtration 100-200 litres per hour per square

metre of filter area3000-6000 litres per hour per square metre of filter area

Efficiency High for bacteria but low for turbidity and colour removal

High for turbidity and colour but low for bacteria removel

Head loss 0.15 to 0.75m 3 to 3.5mFilter material (sand) 600-900mm thick, 0.2 to 0.3mm

diameter and 2-3 uniformity coeff.450-600mm thick, 0.35 to 0.6mm diameter and 1.2-1.7 uniformity

Base material (gravel) 300-750mm thick 3 to 65 mm diameter gravel

600-900mm thick of 3 to 40 mm diameter gravel

7.2 DESIGN OF SLOW SAND FILTER

A slow sand filter consists basically of the following components:

• Housing: a tank with controlling accessories in order to house water and filter materials and subsequently control filtration process.

• Water layer: 0.5 to 1.5m of water above the filter bed (sand)

• Filter layer: 0.6 to 0.9m thick, 0.15 to 0.35mm effective diameter sand layer with a uniformity coefficient of 2 to 3. The uniformity coefficient (UC) of sand is defined as d60/d10. d10 and d60 are defined as the sieve sizes in mm that permit passages of 10% and 60% by weight of the sample sand respectively. For example, UC of sand sample presented in Figure 7.3 with d60 =1.25mm and d10 = 0.32mm is 3.9.

Sieve Analyses of SSF Sand

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0.1 1.0 10.0

Grain size (mm)

% p

assi

ng b

y w

eigh

t

1.25mm0.32mm

Figure 7.3: Sieve Graph of Typical Sand Sample

• Drainage system: 0.3 to 0.75m thick graded gravel in four equal layers with effective diameters as:

o Top layer: 3-6mm

o Intermediate layer 1: 6-20mm


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o Intermediate layer 2: 20-40mm

o Bottom layer: 40-65mm

Example 7.1: Design of Slow Sand Filter

Find the plan area of a slow sand filter required for supplying a village with 220 households. The filter tank is located immediately downstream of the proposed intake with an off-take capacity of 1.5 l/s of continuous flow from a nearby stream called Dokhani. The d60 and d10 of the sand available in the village are 0.3mm and 0.15mm respectively.

Uniformity Coefficient (UC) of the given sand is

UC = d60/d10

= 0.3/0.15

= 2 which is within the limit of 2 to 3, hence ok.

The standard rate of flow of a slow sand filter is 100-200 litres/hour/square meter of filter area.

Total hourly inflow V = 1.5 l/s *(60*60s)/hour

= 5,400 litres/hour

Assuming a rate of filtration as 150 litres/hour/m2, the required area of filter is

A =5,400/150

= 36m2

Using an aspect ratio (L/B) of 4, breadth of the filtration tank (B) is given by:

L*B = A

Or, 4*B*B = A

Or, B =√ (A/4)

=√ (36/4)

= 3m

The length of the tank L = 4 * 3 = 12 m.

Depth of the tank is the summation of 0.3m free board, 1m water, 0.6m sand and 0.6m gravel (totalling 2.5m). Three parallel perforated HDPE pipes are used for collecting water to the system. Alternatively, the under-drainage can also be provided with a main central drainage connected by six parallel lateral drainages. The outcomes of this calculation are presented in Drawing no 2882-0033-05.

7.3 DESIGN OF RAPID SAND FILTER

A rapid sand filter consists basically of the following components:

• Housing: a tank with controlling accessories in order to house water and filter materials.


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• Water layer: 0.5 to 1.5m of water above the filter bed (sand)

• Filter layer: 0.6 to 0.9m thick, 0.35 to 0.60mm effective diameter sand layer with a uniformity coefficient of 1.2 to 1.7 (coarser than SSF).

• Drainage system: 0.45 to 0.60m of graded gravel in four equal layers as:

o Top layer: 3-6mm

o Intermediate layer: 6-20mm

o Intermediate layer: 20-40mm

o Bottom layer: 40-65mm

Example 7.2: Design of Rapid Sand Filter

Find the area of a rapid sand filter required for supplying a village with 1200 households. The filter tank is located immediately downstream of the proposed intake with an off-take capacity of 10 l/s of continuous flow.

Total hourly flow V = 10 l/s *(60*60s)/hour

= 36,000 litres/hour

Assuming a rate of filtration as 4000 litres/hour/m2, the required area of filter is

A = 36,000/4000

= 9 m2

Using an aspect ratio (L/B) of 4, breadth of the filtration tank (B) is given by:

B =√ (A/4)

=√ (9/4)

= 1.5m

The length of the tank L = 4 * 1.5 = 6 m.

Depth of the tank is the summation of 0.3m free board, 1.5m water, 0.6m sand and 0,6m (totalling 3.0m). The under-drainage is provided by providing a main central drainage connected by three parallel lateral drainages.

7.4 GRAVITY FILTER DESIGN PROGRAM BRIEFING & EXAMPLES

Example 7.1 is taken as a typical example for calculating the same parameters of filter tank design presented in a spreadsheet called “Filter”. As presented in Figure 7.4, two drawings/sketches of the design with dynamic dimensions are also presented.


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Date 17-Jun-2008 Revision 2006.05Spreadsheet Developed by: Mr. Pushpa Chitrakar, Engineering Advisor, UNHABITAT, Afghanistan.Project Sayed Baba MHP Designed by:Location Saighan, Bamyan Checked by: CDC/CCDC Sayed Baba MHP

Design flow, qi (l/s) 1.5 5400.000Filtration Type Slow 36.000Rate of filtration, q (l/hr/m2) 150 ok 3.000Aspect Ratio, Ar 4 12.000Depth of water (m) 1.0 Sand (m) 0.6 Gravel (m) 0.6

12

3

1 (m)

0.6 (m)

0.6 (m)

Slow Sand Filter Tank SizingUnited Nations Human Settlements Programme (UN-HABITAT), Afghanistan

Hourly inflow, Qh (l/hr)Filter area, A (m2)

Length, L (m)Width of tank, W (m)

Central Drain

Inlet chamber Outlet chamber

lateral Drains

Raw water inlet

Clear water outlet

Sand

Gravel

channel

floor

Outlet chamber

filtering Head

Adjustable Telescopeic Tube

Outlet for filtered water

Water

Figure 7.4: Sedimentation Tank Sizing spreadsheet “SedimentationTank”


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8 RESERVOIR TANK DESIGN

8.1 INTRODUCTION

A reservoir tank is used for storing water when the quantity of supplied water is higher than the demand at the considered time point and for supplying the stored water when the demand is higher than the supply. Factors affecting the size and type of a reservoir tank are:

• Water source (ground or surface water): Storing of water utilizing surface water is a continuous process (continuous supply flow). On the other hand, underground water is collected in wells and pumped intermittently to elevated tanks in water supply projects that utilize underground water.

• Demand patterns of users as described in chapter 4.

• Allocated cost.

• Topography of tank location (i.e., elevated tanks in flatter topography)

8.2 GRAVITY FED RESERVOIR TANK DESIGN

As stated above, gravity fed reservoir tanks get continuous supply of water from intakes. In this kind of system, the intake is generally far from the supply point. A transmission pipe in this system is generally smaller than that provided for well fed reservoir tanks. Procedures for assessing need of reservoir of a gravity fed reservoir are:

• Calculate demands

• Calculate potential sources

• Define system: A continuous supply system is provided if the total daily supply equal to or more than the total daily demand. Otherwise, an intermittent supply system is provided to suppress the total demand within the total supplied quantity of water.

• Define demand regime: Defining regimes consists of dividing the total daily demand into time slots along with percentage daily demands. A typical example of demand regime recommended by NSP, Afghanistan for rural areas is presented in Table 8.1:

Table 8.1: A typical demand regime Time (from - to) Duration % Demand

19.00 5.00 10 hrs 0% 5.00 7.00 2 hrs 25% 7.00 12.00 5 hrs 35%

12.00 17.00 5 hrs 20% 17.00 19.00 2 hrs 20%

• Assess the need of a reservoir: A reservoir tank is not necessary if the supply at any point of time is equal to or more than the corresponding demand. A reservoir tank is provided to store water if this criterion does not match. The total demand at any point is calculated as the product of the total number of taps by 0.225 l/s. 0.225 l/s is the average tap discharge. Provision of reservoir tanks are generally economical if the distance from the proposed intake to the supply point is relatively long (usually more than 500m).


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8.3 DESIGN PROCEDURES OF GRAVITY FED RESERVOIR TANKS

Reservoir tank fed by gravitational force consists of calculating safe yield (l/s) by balancing the total daily demand with the total daily supply. The design procedures are as:

• Equate the total daily demand (Dd) to the total daily supply (Sd). Calculate safe yield in litre per second that is needed to be fed into the system continuously.

• Calculate hourly supply and demand in m3.

• Calculate total supplies (duration * hourly supply) and demands (percentage usage * daily demand) for the given demand regime.

• Calculate the size of the tank so that the total supply is equal to the total demand meaning there is no spilling at any time. Filling of the tank occurs when the supply is more than the demand. Stored water is withdrawn when the supply is less than the corresponding demand.

Example 8.1: Gravity Fed Reservoir Tank Design

Calculate the size of a reservoir tank of a gravity fed water supply system considering following inputs:

• The source is not near the proposed reservoir tank location and continuous supply should be limited to 2 l/s maximum.

• Total Daily Demand (m3/s) = 115.183

• Demand regime as

Time (from - to) Duration % Demand 19.00 5.00 10 hrs 0% 5.00 7.00 2 hrs 25% 7.00 12.00 5 hrs 35%

12.00 17.00 5 hrs 20% 17.00 19.00 2 hrs 20%

Safe yield:

Assume the size of reservoir tank to be roughly one third of the total demand i.e., 40 m3.

Safe yield (q) = total daily supply in litres per second.

q (l/s) = Total Daily Supply in m3/s*1000/86400

= Total Daily Demand (m3/s) *1000/86400

= 115.183 *1000/ 86400

= 1.333 l/s

= 1.500 l/s (say)

Supplies and Demands:

First Regime (19: to 5:00) i.e., 10 hours.


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Hourly supply = 1.500/1000 * 60*60 = 5.4 m3 / hour

Total water supply during this period = 10 hrs * 5.4 m3 / hour = 54 m3

Total demand = 0

Difference = supply –demand = 54 -0 = 54 m3

Water in the tank = water in the tank (from previous) + difference

= 0 + 54

Since the tank can only store 40m3, any additional supplied water will be spilled.

Second regime (5:00 to 7:00) i.e. two hours:

Total water supply during this period = 2 hrs * 5.4 m3 / hour = 10.8 m3

Total demand = 25% of 115.183

=28.796 m3

Difference = supply –demand

= 10.8 - 28.796 = -17.996 m3 (water is withdrawn)


= 40 + (-17.996)

= 22.004

The summary of the calculations for other regimes are presented in Table 8.2. It should be noted that the water in the tank should not be negative. If it is negative at any regime, increase the size of the tank and repeat all the process until water in the tank is positive. Alternatively, the safe yield can also be increased to make the water in the tank to be positive. The choice between these options depends up on the distance between the source and the proposed tank and availability of safe yield.

Table 8.2: Summary of Reservoir Tank Calculations (all volumes are in m3)

Time period (from - to) Duration % Demand Demand Supply Diff Water in

tank 19.00 5.00 10 hrs 54.000 54.000 40.000

5.00 7.00 2 hrs 25% 28.797 10.800 -17.997 22.003 7.00 12.00 5 hrs 35% 40.315 27.000 -13.315 8.688

12.00 17.00 5 hrs 20% 23.037 27.000 3.963 12.651 17.00 19.00 2 hrs 20% 23.037 10.800 -12.237 0.413

Total 24 hrs 100% 115.183 129.600

8.3.1 Gravity Fed Reservoir design Program Briefing & Examples

The manual calculations presented in Examples 4.1 and 8.1 are taken as inputs for calculating the same parameters in the presented spreadsheet called “ReservoirTank”. The first part of the spreadsheet calculates total demands for different categories of consumptions for a given time span (usually 10 to 20 years of time). The second part of the spreadsheet calculates total


38

supplies up to three spring or stream sources. Based on the demand-supply relations and taps numbers, the spreadsheet recommends the need of a reservoir.

The final part of the spreadsheet calculates the size of the proposed reservoir tank. It is worth noting that the calculations are based on the daily (24 hours) demand-supply relationships.

The tank size calculations use in-built iterative process of MS Excel and can generate errors (such as the size of the tank is millions of cubic meters or very high negative numbers). In such a case select the last cell of the “Water in the Tank” data, press F2 and press Enter.

25-Apr-2008Spreadsheet Developed by: Mr. Pushpa Chitrakar, Engineering Advisor, UNHABITAT, Afghanistan.Revision 2006.05Project Khawal CWSS Calculated by:Location Bamyan Centre Checked by: CDC/CCDC Khawal CDC

Population Growth rate (i) 3% Design life 20 YearsNumber of taps Tn 7 Flow/tap (l/s) 0.225Demand Table Supply Table

Particular UnitsUsers per

unitIndividual

Demands (l/day)Total demand

(l/d) Source Name Safe Yield (l/s)Nr of Family 220 6 45 59400 Source #1 Dokhani river 1.500Students (day-scholar). 1 400 5 2000 Source #2Students (boarding) Source #3Mosques 1 1320 1.8 2376 129.6Hospitals & health posts with bedsHealth clinic without beds Demand and Supply SummaryOthers (Government offices, etc) Present

At the end of year 20

Total demand (m3/day) 63.776 Demand 63.776 115.187Supply 129.600 129.600

Need of reservoirFlow/tap for open system 0.2188 Reservoir is needed Population

Present 1320Capacity of Reservoir Tank (m3) At the end of year 20 2384Demand and Supplies are in m3/day Optimum/Provided (m3/s) 40Schedule I

Duration % Demand Demand Supply DiffWater in the

tankPeak demand

factor19.00 5.00 10 hrs 54.000 54.000 40.0005.00 7.00 2 hrs 25% 28.797 10.800 -17.997 22.003 3.007.00 12.00 5 hrs 35% 40.315 27.000 -13.315 8.688 1.68

12.00 17.00 5 hrs 20% 23.037 27.000 3.963 12.651 0.9617.00 19.00 2 hrs 20% 23.037 10.800 -12.237 0.413 2.40

40

Demand and Gravity Reservoir Size CalculationsUnited Nations Human Settlements Programme (UN-HABITAT), Afghanistan

Total yield (m3/day)

tank size Ok

Time period (from - to)

Comment:Supply > Demand, hence ok

Figure 8.1: Gravity Fed Reservoir Sizing spreadsheet “ReservoirTank”

8.4 DESIGN OF WELL FED RESERVOIR TANKS

Reservoir tank fed by ground water sources consists of calculating safe yield (l/s) by balancing the total daily demand with the pumped total daily supply. The design procedures are as:

1. Calculate total daily demand (Dd) as in gravity fed reservoir tank design.

2. Calculate well yield based on hydro-geological data and well testing. Most of these data are not known in Afghanistan. Therefore, assume the well yields based on the well data of nearby existing wells. Calculate potential total daily supply (Ds).


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3. Check whether the yield is adequate for meeting the daily demand. In case the yield is not adequate, alternative wells should be proposed.

4. Calculate hourly supply and demand in m3 for 24 hours.

5. Calculate total supplies (duration * hourly supply) and demands (percentage usage * daily demand) for the given demand regime. The demand regime in this system should also be divided into to hours.

6. Select well dimensions and pump specifications. The pump should be selected based on performance data (stage-discharge relationship).

7. Select the size of the reservoir tank (generally 25 m3 in community water supply systems having up to 300 households). Select switch “On” of the pump switch data until water in the tank is not negative.

8. Repeat step 7 until satisfactory result is obtained in other cells of “water in the tank” (no negative water in the tank). It should be noted that the step 7 is a “hit and trail” method and need some practical experience.

Example 8.2: Well Fed Reservoir Tank Design

Calculate the size of a reservoir tank considering following inputs:

• Water is supplied by a 0.45m diameter well that can house 100mm pump. The water surface level of the proposed elevated tank is 12m above the ground. The designed total working head of pumping water is 70m.

• Total Daily Demand (m3/s) = 115.183

• Designed well yield is 3 l/s.

• Demand regime as Time period (from - to) Duration % Demand

4.00 5.00 1 hrs 0.00% 5.00 6.00 1 hrs 12.50% 6.00 7.00 1 hrs 12.50% 7.00 8.00 1 hrs 7.00% 8.00 9.00 1 hrs 7.00% 9.00 10.00 1 hrs 7.00%

10.00 11.00 1 hrs 7.00% 11.00 12.00 1 hrs 7.00% 12.00 13.00 1 hrs 4.00% 13.00 14.00 1 hrs 4.00% 14.00 15.00 1 hrs 4.00% 15.00 16.00 1 hrs 4.00% 16.00 17.00 1 hrs 4.00% 17.00 18.00 1 hrs 10.00% 18.00 19.00 1 hrs 10.00% 19.00 20.00 1 hrs 0.00% 20.00 21.00 1 hrs 0.00% 21.00 4.00 7 hrs 0.00%

Total 24 hrs 100%


40

Safe yield:

Daily yield of well = safe yield (l/second) * 86400 second in litres

= safe yield (l/second) * 86400 second /1000 m3

= 3 * 86400/1000

= 259.2 m3

Since the daily well yield is higher than the daily demand of 115.187 m3, the yield is adequate and selected for further design consideration.

Supplies and Demands:

A 50Hz 4” Italian pump manufactured by Hydro Pompe Group is selected. From the pump performance diagram presented in Figure 8.2, a 5.5kW H4K26 is selected with a lifting capacity of 250 litres per minute at 70m head. Let’s choose a 25m3 elevated reservoir tank. A summary of calculations are presented in Table 8.3.

First Regime (5:00: to 6:00)

Hourly supply = 250/1000 * 60 = 15 m3 / hour

Total demand = 12.5% of 115.183

=14.398 m3

Difference = supply –demand = 15 - 14.398 = 0.602 m3 (water is stored)


= 13.481 + 0.602 = 14.083

As presented in Table 8.3, 13.481 m3 of water is already accumulated in the tank from the previous day. As stated earlier, this is an iterative process and this value is taken from a spreadsheet called “ReservoirTankPump”.

Table 8.3: Summary of Reservoir Tank Calculations (all volumes are in m3)

Time period (from - to) Duration % Demand Demand/hr Pump on/off Supply Difference

Water in the tank

Spilling / Drawdown

4.00 5.00 1 hrs 0.00% Off 13.481 storing of 0 5.00 6.00 1 hrs 12.50% 14.398 On 15.000 0.602 14.083 storing of 0.602 6.00 7.00 1 hrs 12.50% 14.398 On 15.000 0.602 14.685 storing of 0.602 7.00 8.00 1 hrs 7.00% 8.063 On 15.000 6.937 21.622 storing of 6.937 8.00 9.00 1 hrs 7.00% 8.063 On 15.000 6.937 25.000 spilling of 3.559 9.00 10.00 1 hrs 7.00% 8.063 Off -8.063 16.937 drawdown of 8.063

10.00 11.00 1 hrs 7.00% 8.063 Off -8.063 8.874 drawdown of 8.063 11.00 12.00 1 hrs 7.00% 8.063 On 15.000 6.937 15.811 storing of 6.937 12.00 13.00 1 hrs 4.00% 4.607 On 15.000 10.393 25.000 spilling of 1.203 13.00 14.00 1 hrs 4.00% 4.607 Off -4.607 20.393 drawdown of 4.607 14.00 15.00 1 hrs 4.00% 4.607 Off -4.607 15.785 drawdown of 4.607 15.00 16.00 1 hrs 4.00% 4.607 Off -4.607 11.178 drawdown of 4.607 16.00 17.00 1 hrs 4.00% 4.607 On 15.000 10.393 21.570 storing of 10.393 17.00 18.00 1 hrs 10.00% 11.519 On 15.000 3.481 25.000 spilling of 0.051 18.00 19.00 1 hrs 10.00% 11.519 Off -11.519 13.481 drawdown of 11.519 19.00 20.00 1 hrs 0.00% Off 13.481 storing of 0 20.00 21.00 1 hrs 0.00% Off 13.481 storing of 0 21.00 4.00 7 hrs 0.00% Off 13.481 storing of 0

Total 24 hrs 100% 115.187 120.000


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Figure 8.2: Pump Performance Charts for H4K Italian Pumps

26


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8.4.1 Well Fed Reservoir Design Program Briefing & Examples

The manual calculations presented in Examples 4.1 and 8.2 are taken as inputs for a typical example for calculating the same parameters in the presented spreadsheet called “ReservoirTankPump”. The first part of the spreadsheet calculates total demands for different categories of consumptions for a given time span (usually 10 to 20 years of time). The second part of the spreadsheet calculates potential yield from the proposed well. The spreadsheet with these calculations is presented in Figure 8.3.

The final part of the spreadsheet calculates the size of the proposed reservoir tank. The tank size calculations use in-built iterative process of MS Excel and can generate errors (such as the size of the tank is millions of cubic meters). In such a case select the last cell of the “Water in the Tank”, press F2 and press Enter.

22-May-2008Spreadsheet Developed by: Mr. Pushpa Chitrakar, Engineering Advisor, UNHABITAT, Afghanistan.Revision 2006.05Project Khawal CWSS Calculated by:Location Bamyan Centre Checked by: CDC/CCDC Khawal CDC

Population Growth rate (i) 3% Design life 20 Years Pump SpecificationsNumber of taps Tn 7 Flow/tap (l/s) 0.225 5.50Demand Table 250.00

Particular UnitsUsers per

unit

Individual Demands

(l/day)

Total demand

(l/d) WellNr of Family 220 6 45 59400 0.450Students (day-scholar). 1 400 5 2000 3.000Students (boarding) 259.200Mosques 1 1320 1.8 2376Hospitals & health posts with bedsHealth clinic without beds Demand and Supply SummaryOthers (Government offices, etc) Present At the end of year 20

Total demand (m3/day) 63.776 Demand 63.776 115.187Population Supply 120.000 120.000Present 1320At the end of year 20 2384Schedule: Demand and Supplies are in m3/day

Duration % DemandDemand /

hrPump on/off Supply

Difference

Water in the tank Spilling / Drawdown

4.00 5.00 1 hrs Off 13.481 storing of 05.00 6.00 1 hrs 12.50% 14.398 On 15.000 0.602 14.083 storing of 0.6026.00 7.00 1 hrs 12.50% 14.398 On 15.000 0.602 14.685 storing of 0.6027.00 8.00 1 hrs 7.00% 8.063 On 15.000 6.937 21.622 storing of 6.9378.00 9.00 1 hrs 7.00% 8.063 On 15.000 6.937 25.000 spilling of 3.5599.00 10.00 1 hrs 7.00% 8.063 Off -8.063 16.937 drawdown of 8.063

10.00 11.00 1 hrs 7.00% 8.063 Off -8.063 8.874 drawdown of 8.06311.00 12.00 1 hrs 7.00% 8.063 On 15.000 6.937 15.811 storing of 6.93712.00 13.00 1 hrs 4.00% 4.607 On 15.000 10.393 25.000 spilling of 1.20313.00 14.00 1 hrs 4.00% 4.607 Off -4.607 20.393 drawdown of 4.60714.00 15.00 1 hrs 4.00% 4.607 Off -4.607 15.785 drawdown of 4.60715.00 16.00 1 hrs 4.00% 4.607 Off -4.607 11.178 drawdown of 4.60716.00 17.00 1 hrs 4.00% 4.607 On 15.000 10.393 21.570 storing of 10.39317.00 18.00 1 hrs 10.00% 11.519 On 15.000 3.481 25.000 spilling of 0.05118.00 19.00 1 hrs 10.00% 11.519 Off -11.519 13.481 drawdown of 11.51919.00 20.00 1 hrs Off 13.481 storing of 020.00 21.00 1 hrs Off 13.481 storing of 021.00 4.00 7 hrs Off 13.481 storing of 0

Total 24 hrs 100% 115.187 120.000

25Decreasable tank size

Demand and Pumped Reservoir Size CalculationsUnited Nations Human Settlements Programme (UN-HABITAT), Afghanistan

Time period (from - to)

Comment:Supply > Demand, hence ok

Capacity (kW)Capacity (l/min)

Yield (l/s)Diameter (m)

Maximum Yield (m3/d)

Figure 8.3: Well Fed Reservoir Sizing spreadsheet “ReservoirTankPump”


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9 PIPE NETWORK DESIGN

9.1 INTRODUCTION

This chapter deals with the design processes of transmission (source to reservoir) and distribution (reservoir to tap stands) pipe networks where water is conveyed by gravitational energy of moving water. The gravitational energy due to gravity at site is equal to the elevation difference between points such as between the intake and the reservoir tank sites. This elevation difference is termed as the head in metres. One metre of head produces 0.981 atmosphere of pressure.

This gravitational energy is utilized for conveying the desired flow through a series of selected pipes. Design or selection of pipes includes:

• Measuring of driving heads (elevation drops)

• Measuring of pipe lengths

• Choosing required flows

• Choosing required residual heads (the end-of-pipe pressures)

• Choosing pipe diameter that matches with the desired head losses (driving head – residual head). Losses of heads occur due to friction and turbulent along the flow path. It is worth noting that different pipe sizes and pipe materials have different flow capacities for a given elevation drop. A flow is called a natural flow when the residual head is zero.

Since some basic knowledge of hydraulic theories is essential for designing pipe networks, a brief and simplified overview of hydraulic theories useful in understanding gravity water flow in pipes are presented in the following sections:

Continuity of Flow: For constant water flow in a pipe, flow at one part of a pipe is equal to flow at any other part of the pipe, as shown by:

Point A Flow (QA) = Point A Velocity x Point A Area

= Point B Velocity x Point B Area = Constant

Changing of pipe cross sectional area (a larger or smaller pipe) will cause a change in velocity. This phenomenon can be utilized when selecting a pipe size at normal or pipe combination or negative pressure cases.

Water at Rest: When no water is flowing in a gravity-pressured pipe (as when all taps are closed), it is in static equilibrium. Water levels are at static levels and pressures in the pipe are termed as static heads. As no water is flowing there is not energy loss to friction and turbulent and the pressures in the pipe at their highest at all points, highest pressure being at the lowest point.

Water in Motion: When water is flowing in a pipe, friction loss occurs that reduces pressure energies at all point along the pipe. With a constant flow (water in motion), a system is said to be in dynamic equilibrium and pressures are termed as dynamic heads.

Hydraulic Grade Line (HGL): A line connecting free water surface points along the flow path. The line at water at rest condition (static equilibrium) is termed as static HGL where as it is termed as dynamic HGL when water is in motion (dynamic equilibrium). Static HGL is horizontal


44

whereas dynamic HGL is sloped downwards from the water inlet to the outlet. In general, the dynamic HGL is called the HGL.

Figure 9.1: Longitudinal section and water profiles of a water supply system

Friction: When water is flowing along the pipe, a certain amount of energy is lost by the friction of water against the pipe wall (skin friction) and fittings, entries and exits of the pipe and change of pipe cross sections (turbulence losses) and is determined by:

• The pipe wall roughness

• The velocity of the water

• Change of velocity direction creating turbulence due to fittings, etc.

Friction losses (skin friction) for water supply pipes are calculated using Hazen-Williams as:

Q = 0.2785*C*D2,63*S0.54

Where, Q = discharge (m3/s) C = Hazen-Williams friction coefficient (typically, 140 for HDPE and 100 for GI), the recommended values of C are given in Table 5.01. D = internal diameter of pipe (m) S = Hydraulic gradient (energy slope) = 1:N = HLf/L

The frictional loss per 100m of pipe length (% frictional loss, %HLf) can be calculated as:

%HLf = (Q/(0.2785*C*D^2.63))^(1/0.54)*100

In practice, percentage frictional losses are tabulated for quick manual calculations. A Sample of such a table is presented in Table 9.2. The tabulated percentage frictional losses may be quite different than those calculated analytically. It is also recommended that the tabulated


45

percentage frictional losses should be used for GI pipes. Cells with “VLOW” flags indicate that the pipe for the stated flows have lower velocities than recommended. “VHIGH” in the table stands for higher velocity.

Table 9.1: Recommended Values of C Pipe material Minimum C Maximum C

Cast iron 100 120 Galvanized steel 55 120

Steel 100 140 Concrete 100 140

Asbestos cement 120 140 Plastic pipes (PVC, HDPE, etc) 120 140

Glass reinforce plastic pipes (GRP) 140 145

Table 9.2: % Head loss for HDP Pipe (ISI Standard) Thickness (mm) 2.2 2.55 3.05 3.95 2.55 4.85 3.15 6 3.9

ID (mm) 11.60 14.90 18.90 24.10 26.90 30.30 33.70 38.00 42.20OD (mm) 16 20 25 32 32 40 40 50 50Pressure 10kg/cm2 10kg/cm2 10kg/cm2 10kg/cm2 6kg/cm2 10kg/cm2 6kg/cm2 10kg/cm2 6kg/cm2

Flow (l/s) 16IV 20IV 25IV 32IV 32III 40IV 40III 50IV 50III0.050 V LOW V LOW V LOW VLOW V LOW VLOW VLOW VLOW VLOW0.100 12.60 3.70 1.20 0.40 V LOW V LOW V LOW V LOW V LOW0.110 14.93 4.35 1.50 0.50 0.30 V LOW V LOW V LOW V LOW0.120 17.44 5.07 1.70 0.50 0.30 V LOW V LOW V LOW V LOW0.130 20.12 5.84 2.00 0.60 0.40 V LOW V LOW V LOW V LOW0.140 22.97 6.66 2.20 0.70 0.40 V LOW V LOW V LOW V LOW0.150 26.00 7.53 2.50 0.80 0.50 V LOW V LOW V LOW V LOW0.160 29.19 8.45 2.80 0.90 0.50 V LOW V LOW V LOW V LOW

For example, the friction factor for 20IV (pressure bar of 10) for a flow of 0.15 l/s is 7.53m per 100m of pipe. In case a flow is not listed in the flow column, the friction factor should be calculated by linear interpolation. As presented in Figure 9.2, the friction factor for a flow of 0.225 l/s for the same pipe is calculated as 5.455 m per 100m of pipe using the straight line interpolation method.

Head loss chart for HDP Pipe(ISI Standard)ID (mm) 14.90OD (mm) 20pressure 10kg/cm2

FLOW 25IV Q F0.220 5.070.230 5.84

25IVF = F1+(F2-F1)/(Q2-Q1)*(Q-Q1)F = 5.07+(5.84-5.07)/(0.230-0.220)*(0.225-0.220)F = 5.455

0.225 5.455

Interpolation of Friction Factors5.84

5.075.005.105.205.305.405.505.605.705.805.90

0.215 0.220 0.225 0.230 0.235

Flow (l/s)

Fric

tion

Fact

or (%

)

Figure 9.2: Interpolation for % frictional factor for unlisted flow of 0.225 l/s.

Turbulent head losses are the summation of head losses at entrance, bends, and exits and at every change of velocity a long the pipe and can be expressed as:

HLt = ∑ K * v2/2g

Where,

K = turbulent coefficient (inlet = 0.5,outlet = 1.0, etc)


46

v = pipe velocity (m/s) = Q/Area of pipe = 4*Q/(π*D2). The velocity should preferably be limited in a range of 0.4 to 3 m/s.

Head losses at bends and velocity change points are generally not considered in designing community based water supply systems. In order to compensate these losses, equivalent pipe lengths of fittings (multiple of pipe diameter) are considered and added to the total length of the pipe. A summary of L/D ratio for different fittings is presented in Table 9.3. Alternatively, an additional 5% to 10% of total head loss is considered to be adequate for compensating additional head losses due to turbulent losses.

Table 9.3: Equivalent Pipe Lengths of Fittings Fittings L/D RatioTee (run - side) 68Tee (run - run) 27Elbow (90o, short radius) 33Union 7Gate Valve (fully open) 7Free entrance 29Screened entrance 150

Example 9.1: Natural Flow

Design a HDPE pipe for a system presented in Figure 9.1 for the following input parameters:

• The system is in natural flow condition.

• Length of the pipe is 350m (an additional equivalent length of 5% is already included for turbulence losses).

• There is a gross driving head of 23m.

The energy slope (S = 1/N) is = desired head loss /pipe length

= 23/350 = 0.065714286

Consider using 25mm diameter HDPE pipe with C = 140 and PN = 10, thickness = 3.05mm.

Flow capacity of the pipe as per Hazen-Williams equation

Q = 0.2785*C*D2.63*S0.54

= 0.2785*140*((25-2*3.05)/1000)2.63*0.0657142860.54

= 0.000262775 m3/s

= 0.262775 l/s

= 15.767 l/min

Checking of velocity whether it is within 0.4 to 3 m/s

V = 4*Q/(π*D2)

= 4*0.000262775/(π*((25-2*3.05)/1000)2)

= 0.936635372 m/s, hence within the limit.


47

9.2 SPECIAL CASES: CRITICAL HYDRAULIC CONDITIONS

9.2.1 Combination Pipes

When a single pipe size does not give the desired friction head loss, a combination of two pipes is recommended and the smaller pipe length is calculated as:

100 x H - (Flarge x L) Smaller Pipe Length (Lsmall) (m) = ---------------------------

(Fsmall – Flarge)

Where: H = the total head available for friction loss (m) = desired head loss (m)

L = total pipe length (m)

Flarge = % friction loss in the larger pipe (metre per 100 metres)

Fsmall = % friction loss in the smaller pipe (metre per 100 metres)

The length of the larger pipe Llarge(m) = L - Lsmall

It is worth noting that the small pipe should be placed downstream of the large pipe. This phenomenon is presented in Example 9.2.

Example 9.2: Combination Pipes

Design a water supply system using the same conditions as in Example 9.1 for the following input parameters:

• Desired residual head of 10m

• Design flow of 0.263 l/s

• Ignore turbulent head losses because additional equivalent lengths are already included in calculating the total length of the pipe.

Consider using 32mm diameter HDPE pipe with C = 140 and PN = 10, thickness = 3.95mm.

Frictional head loss factor by Hazen-Williams is

%HLf = (Q/(0.2785*C*D^2.63))^(1/0.54)*100

= (0.000262775 /(0.2785*140*((32-2*3.95)/1000)^2.63))^(1/0.54)*100

= 2.012 m per 100m

Total head loss HL = L* %HLf

= 350 * 2.012/100

= 7.042m

Residual head = total head – head loss

= 23 – 7.042


48

= 15.958 m

Since the residual head is more than 10m, a combination pipes of 32mm and 25mm is considered for further calculations.

Frictional head loss factor for 25 mm HDPE pipe:

%HLf = (Q/(0.2785*C*D^2.63))^(1/0.54)*100

= (0.000262775 /(0.2785*140*((25-2*3.05)/1000)^2.63))^(1/0.54)*100

= 6.571 m per 100m

Desired head loss (H) = total head – residual head

= 23-10

= 13m

Length of Smaller Pipe (25mm) Length

(Lsmall) (m) = (100 x H - (Flarge x L)) /(Fsmall – Flarge)

L25 = (100*13-(2.012*350))/(7.042-2.012)

= 118.449 m

Head loss due to smaller pipe, HL25 = L25 * %HLf25/100

= 118.449 * 6.571/100

= 7.783 m

Llarge = L 32 = L – L25

= 350 – 118.339

= 261.331m

Head loss due to larger pipe, HL32 = L32 * %HLf32/100

= 261.331 * 2.012/100

= 5.258 m

Checking of total head loss HL = HL25 + HL32

= 7.783 + 5.258

= 13.041 m hence ok (0.041 m of error is due to rounding of numbers).

The results of pipe combination are presented in Figure 9.1.

9.2.2 Negative Pressure

Negative pressure (pressure less than atmospheric) often occurs where the pipe leaving the water source is on a flat grade until it goes down a steep hill. This may result in the system


49

failure due to critical siphoning, drawing of air and collapsing of the pipes. Therefore, the HGL should always be above the pipeline (i.e., there should always be a positive pressure in the pipe). The preferable solution is to resize the pipe section (bigger pipe, pipe combination or lesser flow). Alternatively, a second parallel pipe can be installed in an existing system. A typical example of negative pressure development is shown in Figure 9.3.

Figure 9.3: Negative pressure along the pipe line

Example 9.3: Negative Pressure

Using the same conditions as in Example 9.1 (23m elevation head, using 350m of 25mm diameter HDPE pipe flowing into a trough), but with uneven grade: 3.5 m fall in 150m then 19.5m fall in the last 200m, as shown in Figure 9.3. What pipe size (s) is needed to prevent a negative pressure in the pipe?

Headloss factor for 25mm diameter HDPE pipe with C = 140 and PN = 10, thickness = 3.05mm is 6.571 m per 100m.

Head loss in the first leg of 150m = 6.571 *150/ 100 m

= 9.857 m.

Negative pressure of 9.857-3.5 = 6.357 m develops since the available fall is only 3.5m. To correct this, different pipe sizes must be selected (larger pipe upstream of smaller pipe).

Headloss factor for 32mm diameter HDPE pipe with C = 140 and PN = 10, thickness = 3.95mm of 2.012 m per 100m (as calculated in Example 9.2) gives a total head loss along the first stretch as

HL 32 = 150*2.012 /100

= 3.018 m, hence ok and the dynamic HGL is 0.482m above the ground.


50

Provide 25mm diameter pipe for the rest of the pipe.

Head available = 23 – 3.018 = 19.982 m

Head loss along 200m of pipe = 200*6.571/100

= 13.142 m

Residual head = 19.982 – 13.142

= 6.840 m

The dynamic HGL are plotted in Figure 9.3.

9.2.3 Air Locks:

Gravity pressured flow is prone to partial or total blockage by trapped air pockets. Air may enter the system either from already trapped air, from inlets, from loose fitting, from dissolved air, etc. Air locks can form either during static conditions or dynamic conditions. Any air that is trapped must be carried downstream to an outlet to ensure continued water flow. A total air lock can form in a pipe which will completely block the flow of water. A partial air lock partially blocks flow reducing the area available for water flow. The total and partial air locks are presented in Figures 9.4 and 9.5 respectively.

Figure 9.4: Formation of a Partial Air Lock

A total air lock forms if the trough height (HT in Figure 9.5) is higher than the summation of all the heights of air columns. Following conditions should be satisfied in order to prevent a total air lock formation:

HT≤ H

Where,

H = driving head = Hs – (H1+H2+..)

Hs = static head

(H1+H2+..) = air lock columns


51

Figure 9.5: Formation of a Total Air Lock

Formation of air locks can be prevented by laying pipe networks that has higher driving heads (lower HT) or providing air release valves at the peaks along the pipe or providing a break pressure tank. The first case is illustrated in Figure 9.6. Proper velocity of flow also helps flushing entrapped air. A summary of flushing velocities to prevent air locks is presented in Table 9.4.

Table 9.4: Flushing Velocities to prevent air locks Nominal pipe size (mm) Flushing velocity (m/s)

16 0.40 20 0.49 25 0.55 32 0.91 40 0.70 50 0.79


52

Figure 9.6: Prevention of Formation of Air Locks by analyzing pipe profiles

Example 9.4: Air Lock

Check the formation of air lock for a system presented in Figure 9.7. The system consists of 32mm diameter PN10 pipe of 350m lone flowing freely into a trough. The route has a rise over a hill of 15m and then up a second slope to the trough that must be at 9m. The design discharge of the system is 7.5 l/min. Recommend alternative options in case an air lock forms.

Figure 9.7: Diagram for Example 9.4

Calculate Available Head

Head available at the high point = 23-15 = 8m above high point to the water source. In case an air lock occur at the high point, there would be only this 8m head for water flow to the trough including friction and lift to the trough.

Calculate the friction loss:

Flow in m3/s Q = 7.5 / 60/1000 = 0.000125 m3/s

Total head loss = L * % HLf

10m


53

= L*(Q/(0.2785*C*D^2.63))^(1/0.54)*100%

= L*(Q/(0.2785*C*D^2.63))^(1/0.54)

= 350* (0.000125 /(0.2785*140*((32-2*3.95)/1000)^2.63))^(1/0.54)

= 1.779m

In no air lock condition: the residual head of (14-1.779 = 12.221m) is available. The elevation of the trough in air lock condition = 8-1.779 = 6.221 m. Therefore, the trough should be located at 6.221m or else water will not reach the trough under water lock conditions.

Alternative recommendations:

1. Increase the flow so that the velocity of the flow is up to the recommended flushing velocity of 0.91m/s (as stated in Table 9.4). Flow through 32mm HDPE PN10 pipe for a driving head of 14m is:

Q = 0.2785*C*D2.63*S0.54

= 0.2785*140*((32-2*3.95)/1000)2.63*(14/350)0.54

= 0.000381 m3/s

= 0.380864 l/s

Flow velocity (V) = 4*Q/(π*D^2)

= 4*0.000381/(π*((32-2*3.95)/1000)^2)

= 0.85322 m/s, not okay since it is less than 0.91m/s

2. Use smaller pipe so that the flow velocity is higher. Flow through 25mm diameter HDPE PN 10 pipe is:

= 0.2785*140*((25-2*3.05)/1000)2.63*(14/350)0.54

= 0.000200983 m3/s

= 0.200983 l/s

= 12.059 l/min


= 4*0.000200983/(π*((25-2*3.05)/1000)^2)

= 0.7163 m/s, okay since it is more than 0.55 m/s as stated in Table 9.4.

3. Install a valve on the outlet to restrict flow to 7.5 l/s and 25mm diameter HDPE PN 10 pipe. Head loss through the pipe is:

HLf = L * %HLf

= L*(Q/(0.2785*C*D^2.63))^(1/0.54)*100/100

= 350*((7.5/60/1000) /(0.2785*140*((25-2*3.05)/1000)^2.63))^(1/0.54)*100/100


54

= 5.81009576 m, hence okay since it is less than the available head of 14m.


= 4*(7.5/60/1000)/(π*((25-2*3.05)/1000)^2)

= 0.44555 m/s, not okay since it is less than 0.55 m/s as stated in Table 9.4.

Consider limiting the flow velocity of 0.55 m/s, flow capacity and other parameters are:

Flow (Q) = V*A = V*(π/4*D^2)

= 0.55*((π/4*((25-2*3.05)/1000)^2)

= 0.000154304 m3/s = 9.2582 l/min, hence okay.

Head loss for this discharge is HLf = L * %HLf

= L*(Q/(0.2785*C*D^2.63))^(1/0.54)*100/100

= 350*(0.000154304/(0.2785*140*((25-2*3.05)/1000)^2.63))^(1/0.54)*100/100

= 8.582 m, hence okay since it is less than the available head of 14m.

4. Install an air release valve at the high point to ensure release of any accumulated air. Either of the considered pipes can be used with the air release valve. Additionally, a valve on the outlet to restrict flow to 7.5 l/min is recommended.

9.3 PIPE SELECTION IN AFGHANISTAN

There is a complete lack of standardization of HDPE pipe in Afghanistan. HDPE pipes manufactured in Pakistan, Iran and Afghanistan are commonly used in water supply systems. Although the brochures of the available pipes state that those pipes are manufactured using DIN8074, DIN8075, EN1555, EN12201, etc, their geometrical parameters differs from one manufacturer to another. Qualities of these pipes are not yet possible to be certified locally. Although there are many manufacturers, pipes and fittings manufactured by the following manufacturers are commonly used in the water supply schemes:

1. Polypark Pipes (Iranian)

2. Herat Polyethylene Company (Afghani)

3. Royal PVC (Pvt) Limited (Pakistani)

4. Samnan Pipes (Iranian)

Pipe specifications by these manufacturers are annexed in Data Sheets and Formats. It is recommended that the actual geometry should be verified with the tabulated data.


55

9.4 A COMPLETE DESIGN

Example 9.5: Pipe Network Design

A pipe network system proposed for one of the Bamyan CDC is presented in Figure 9.5. The project data are also presented in the figure. Design the pipe network systems incorporating a reservoir at joint Jn 00.

Present Population = 220 households

6 people in each family

design horizon = 10 yearsYield of intake is abundant.

Intake (Dokhani Stream)E.2668.26

10m 222m 88m 357m 285m 887

95m

2000m

174m

300m

Number of taps = 7

Flow per tap = 0.225 l/s

Use PE 80 HDPE pipes

Project Data

Use 10m service pipe for taps

Population growth rate = 3%

Per capita daily water demand = 45 l/p/d

E.2630.0Jn 00 (good place for locating RVT)

Tp01Jn01

Jn03Jn02

Jn04 Jn05 Jn06Tp02

Tp03 Tp04 Tp05 Tp06

Tp07

E.2586.19E.2586.19

E.2588.82E.2586.76 E.2584.34 E.2585.67

E.2589.85

E.2582.70 E.2551.84

Figure 9.8: Diagram for Example 8.5

Demand Calculations:

Present population (Po) = Nr of families * persons per family

= 220*6 = 1320 persons

Population at the end the tenth year (Pn) with respect to the present population

Pn = Po (1+i/100)n

P10= 1320 (1+3/100)10 = 1774 persons

Demand (D) = daily water demand * Pn

= 45 l/d/p * 1774 p

= 79,830 l/d = 79.83 m3/d

System Design (Open or closed)

Continuous supply = daily demand/86400


56

= 79,830/86400

= 0.924 l/s (say 0.925 l/s)

= 3.330 m3/hr

It is assumed that the flow is abundant. Since the distance between the source to the proposed reservoir tank location is 2000m, it will be an optimum solution to use reservoir tank with smaller diameter of pipe from the intake to the reservoir tank.

Maximum continuous demand = Nr of taps * tap flow = 7*0.225 = 1.575 l/s

Which is greater than the continuous supply of 0.924 l/s, therefore a reservoir tank is needed.

Reservoir tank design:

Recommended schedule with tank storage during off peak period is considered. A summary of demands and supplies for the recommended schedule is presented in Table 9.5:

Table 9.5: Design of Reservoir

The tank size of 34 m3 was selected by hit and trail method. The basis of fixing the size of the water tank is to have positive water balance in the water tank. Let’s select 35m3.

Intake Design:

Bamyan is a cold place and the stream water is very clean. The upstream has very little settlements. Therefore, provision of filtration is regarded as unnecessary. Chlorination of water during summer is recommended. In absence of chlorination tank, the proposed reservoir tank is recommended to be used.

Let’s choose:

1. A dry stone screening

2. A collection tank with HDPE strainer and a ½” GI inverted air vent

3. A 5m long GI pipe from intake to sedimentation tank (31.8mm)

4. A sedimentation tank.

Gross length of GI pipe: actual lengths + equivalent of pipe lengths for fittings (strainer, air-vent and a glove valve).

L = 5m + (105+27+7)*31.8/1000

= 10.8512m

Time period (from - to) Duration

% Demand Demand Supply Diff

Water in the tank

Peak demand factor

19.00 5.00 10 hrs 33.300 33.300 34.000 5.00 7.00 2 hrs 25% 19.957 6.660 -13.297 20.703 3.00 7.00 12.00 5 hrs 35% 27.940 16.650 -11.290 9.413 1.68

12.00 17.00 5 hrs 20% 15.966 16.650 0.684 10.097 0.96 17.00 19.00 2 hrs 20% 15.966 6.660 -9.306 0.791 2.40


57

Strainer:

A strainer of 63mm diameter HDPE is used (refer to Table 5.1) for the stated flow with the following parameters.

hole diameter = 3.5 mm at 10mm c/c

Total holes = 2 * 255 = 510

Nr of rows = INT(π*dia of strainer/10)

=INT(π *63/10) = 19 rows

Nr of columns = 510/19 = 26.84 columns (say 30 columns)

Min strainer length = 30 * c/c distance = 300mm

Use 400mm long 63mm diameter HDPE strainer.

Headloss calculation

Friction factor (HLf) for Q=0.925 l/s and 31.8 dia GI is 9.893% (From GI Pipe Table)

Exit loss factor K = 1.0

Velocity v = Q/A = (0.925/1000)/(π(31.8/1000)2/4))

= 1.16 m/s

Total head loss with a factor of safety of 1.3 is

= 1.3*(L*HLf+K*v2/2g)

= 1.3*(10.8512* 9.893% +1*1.162/2/9.81)

= 1.485m

Water level at sedimentation tank = 2668.26 – 1.485

= 2666.775m

Design of sedimentation tank:

Choose D=0.7m, B=0.7m, Sediment storage depth = 0.25m

Velocity v = Q/A = (0.924/1000)/(0.7*0.7)

= 0.00189 m/s < 0.05 m/s hence okay

Tank capacity (C) = t*Q, where a detention time of 1800 sec is considered.

= 1800 *0.925/1000

= 1.665 m3

Length of tank L = C/(B*D)

= 1.665 /(0.7 * 0.7)


58

= 3.398m, use 3.5m

Aspect Ratio, L/B = 3.5/0.7 = 5 >4, hence Ok.

The designed intake and sedimentation tank are presented in Figure 9.9. The fittings and other accessories are also presented in the figure.

Pipe design (sedimentation tank to reservoir at Jn 00)

Pipes with PE 80 HDPE and safety factors of 2.0 Polypark (Iranian pipes) are used in all cases. The measured lengths are factored by 1.1 (i.e., 10% more). This will also be considered in head loss calculations. An addition of 5% of gross length is considered enough if the length is measured precisely.

Length (L) = 2000*1.1 = 2200 m

Flow (Q) = 0.925 l/s

HGL of at sedimentation tank, RL1 = 2666.775 m

RL of the second station (RVT) RL2 = 2630m

Available head (H) = 2668.26 – 1.485-2630 = 36.775m

Desired residual head (DRH) = 10m

Desired headloss dH= 36.775-10 = 26.775

Desired headloss factor (DHF) = 26.775 /2200*100 = 1.217%

Referring to HDPEHW table of PolyPark pipes, try 50mm PN 6, 3.7mm thick, %HLf50 = (Q/(0.2785*C*D^2.63))^(1/0.54)*100

= ((0.925/1000) /(0.2785*140*((50-2*3.70)/1000)^2.63))^(1/0.54)*100

= 1.290676 m/100m

Total head loss = HLf50=L*%HL

= 2200*1.290676/100 = 28.39487m> 26.775 m of available head. Hence not okay.

Try 63mm PN 6, 4.7mm thick, %HLf63 = (Q/(0.2785*C*D^2.63))^(1/0.54)*100

= ((0.925/1000) /(0.2785*140*((63-2*4.70)/1000)^2.63))^(1/0.54)*100

= 0.42167 m/100m


= 2200*0.42167/100 = 9.27674m< 26.775 m, which is ok but not economical.

Use combination of these pipes:

Length of 50mm pipe = (Lsmall) (m) = (100 x H - (Flarge x L)) /(Fsmall – Flarge)

= (100*26.775-(0.42167*2200))/(1.290676-0.42167)

= 2013.595 m


59

Length of 63mm pipe = 2200-2013.595 = 186.405 m.

Note that 50 diameter pipe may also be used if residual head of less than 10m is acceptable

Pipe design (reservoir to JCT01)

The pipe downstream of the reservoir is relatively longer and optimizing at this point may have less or even negative residual heads downstream. The, higher residual head at this point is quite helpful.

Length (L) = 300*1.1 = 330 m

Flow (Q) = 7 taps * 0.225 l/tap = 1.575 l/s

HGL of water at RVT, RL1 = 2630 m

RL of Joint 01 (JCT01) RL2 = 2586.19m

Available head (H) = 2630 - 2586.19= 43.81m

Desired residual head (DRH) = 30m

Desired headloss dH= 43.81-30 = 13.81m

Try 50, PN 6, 3.7mm thick %HLf50 = (Q/(0.2785*C*D^2.63))^(1/0.54)*100

= ((1.575/1000) /(0.2785*140*((50-2*3.7)/1000)^2.63))^(1/0.54)*100

= 3.458 m/100m


= 330*3.458/100 = 11.411m < 13.81 m of available head. Hence okay.

Pipes for the other legs are designed in similar manner. The final tabulated calculations and the corresponding drawing are presented in Figures 9.10 and 9.11.

2557

720

3390

35006003800600800600

600

5012

00 2000

850 1485

250

50 700

2070

585

4700

NWL

Dry stone masonry / Gabion

Stone masonry collection chamber63mm dia HDPE,strainer with 3.5mm holes

Gate valve

31.8mm dia GI

sediment washout

63 dia PN 6 HDPE outlet

1:50

Coarse screening

stream 0.5'' dia GI air vent

600

50

Figure 9.9: Intake and Sedimentation tank considered in Example 9.8


60

63,PN6, 255m50,PN6, 1745m

50,P

N6,

330

m

20,PN10, 104.5m

50,P

N6,

101

.4m

16,PN10, 11m

50,PN6, 244.2m

50,PN6, 96.8m

50,PN6, 357m 40,PN6, 313.5

32,PN6, 218m25,PN10, 757m

Intake (Dokhani Stream)E.2668.26

10m 222m 88m 357m 285m 887

95m

2000m

174m

300m

16,PN

10, 11m

16,PN

10, 11m

20,PN

10, 11m

20,PN

10, 11m

E.2630.0Jn 00 (good place for locating RVT)

Tp01Jn01

Jn03Jn02

Jn04 Jn05 Jn06Tp02

Tp03 Tp04 Tp05 Tp06

Tp07

E.2586.19E.2586.19

E.2588.82E.2586.76 E.2584.34 E.2585.67

E.2589.85

E.2582.70 E.2551.84

Figure 9.10: Pipe network design considered in Example 9.8

Summary of PE 80 PipesSN Pipe Dia (mm) Thickness (mm) PN (bar) Length (m)

1 HDPE 16 1.80 10 442 HDPE 20 2.30 10 125.53 HDPE 25 2.80 10 613.84 HDPE 32 2.40 6 361.95 HDPE 40 3.00 6 313.56 HDPE 50 3.70 6 3074.47 HDPE 63 4.70 6 180.3


61

9.5 PIPE DESIGN PROGRAM BRIEFING & EXAMPLES

Two spreadsheets are presented for designing pipes networks. The first spreadsheet “PipeDesignHW” uses analytical method for calculating percentage frictional coefficients by Hazen-Williams method. The second spreadsheet “PipeDesign” uses tabulated data of percentage frictional coefficients. It is worth noting that the tabulated GI friction factors for different pipe diameters with the same coefficient C do not match with the analytically calculated friction factor. Therefore, in case of GI pipes, the second spreadsheet should be used.

The names of the “Station 1” of pipe reaches with free water surfaces have to be started with three specific letters corresponding to the types of the structures as:

SRC for source (such as “SRC at Dokhani stream”)

RVT for reservoir tank (such as “RVT at Khawal”)

BPT for break pressure tank (such as “BPT01”)

SED for sediment tank (such as “SED additional”)

A provision for calculating pipe lengths for pipe combination is also presented in the spreadsheets. The elevation and length of the pipe junction are the final outcome of these calculations that should be input as input variable for the new arbitrary junctions in the main calculation table.

Every new leg of pipe networks has to be started after leaving a blank row. The first two calculation rows of the main spreadsheet have to be copied to all the new legs. The second row of the pasted cells has to be copied to the remaining rows of the considered legs. HGL of the first station of the branching station has to be copied in “HGL station 1” of the blank row.

A friction factor table for HDPE pipes based on PolyPark (Iranian Standards) is presented to speedup the selection process.

Four sets of AutoCAD script commands are also calculated for plotting ground profile, HGL and naming of the joints. Since different vertical and horizontal scales are presentable in most of the water supply profiles, a provision for vertical to horizontal scale ratio is presented. It is worth noting that each profile should be plotted separately. A typical longitudinal profile of the first leg with a horizontal to vertical scale of 1:5 is presented in drawings number 2882-0033-10.

Friction factor tables for HDPE and GI pipes based on ISI (Indian Standards) and DIN are also presented for used by tabulated method that utilized these tables for calculating pipe head losses in “PipeDesign” Spreadsheet.

The outputs by using both the analytical and tabulated methods are presented in Figures 9.11 and 9.12. Pipes from PolyPark were used in analytical method whereas pipes based on Indian Standards were used in tabulated method. Since the internal diameters of pipes in these two standards are different, the outputs are also slightly different.


62

DateSpreadsheet Developed by: Mr. Pushpa Chitrakar, Engineering Advisor, UNHABITAT, Afghanistan. Revision 2007.08Project Sayed Baba MHP Surveyed by: Checked by:Location Saighan, Bamyan Instrument used: Pipe Combination (Xm) Calculation F large pipe (FS) 0.837 F small pipe (FL) 4.341CDC/CCDC Sayed Baba MHP Σ Desired head loss 34.68 HGL at the first station 2601.520 Small dia pipe length (X) 757Material C-Value PE Large pipe 32 2.4 6 Total pipe length L (m) 975 Bigger dia pipe length (Y) 218HDPE 140 80 Small pipe 25 2.8 10 Designed Discharge (l/s) 0.225 HGL at the joint 2595.185GI 100

Frictional head loss

station 1 station 2 Station 1 Station 2 ground design diameterThickness of HDPE PN / GI station 1 station 2 factor (F) (%) total (m)

SRC1 Combination 1 2666.775 2658.634 163.64 180.0 0.924 63 4.70 6 2666.775 2666.018 0.421 0.76 7.38 0.41 abc

Combination 1 RVT1 2658.634 2630.000 1836.36 2020.0 0.924 50 3.70 6 2666.018 2639.998 1.288 26.02 10.00 0.65 abd

RVT1 JCT1 2630.000 2586.190 300.00 330.0 1.575 50 3.70 6 2630.000 2618.588 3.458 11.41 32.40 1.11

JCT1 JCT2 2586.190 2589.850 174.00 191.4 1.350 50 3.70 6 2618.588 2613.613 2.599 4.98 23.76 0.95

JCT2 JCT3 2589.850 2586.760 222.00 244.2 1.125 50 3.70 6 2613.613 2609.084 1.855 4.53 22.32 0.79

JCT3 JCT4 2586.760 2584.340 88.00 96.8 0.900 50 3.70 6 2609.084 2607.896 1.227 1.19 23.56 0.63

JCT4 JCT5 2584.340 2585.670 357.00 392.7 0.675 50 3.70 6 2607.896 2605.068 0.720 2.83 19.40 0.47

JCT5 JCT6 2585.670 2582.700 285.00 313.5 0.450 40 3 6 2605.068 2601.873 1.019 3.20 19.17 0.50

JCT6 Combination 2 2582.700 2595.185 198.18 218.0 0.225 32 2.4 6 2601.873 2600.048 0.837 1.82 4.86 0.39

Combination 2 TAP07 2595.185 2551.840 688.18 757.0 0.225 25 2.8 10 2600.048 2567.185 4.341 32.86 15.34 0.76

2618.588

JCT1 TAP1 2586.190 2586.190 95.000 104.5 0.225 20 2.3 10 2618.588 2604.620 13.367 13.97 18.43 1.21

2613.613

JCT2 TAP2 2589.850 2588.820 10.000 11.0 0.225 16 1.8 10 2613.613 2609.389 38.399 4.22 20.57 1.86

2609.084

JCT3 TAP3 2586.760 2586.760 10.000 11.0 0.225 16 1.8 10 2609.084 2604.860 38.399 4.22 18.10 1.86

2607.896

JCT4 TAP4 2584.340 2584.340 10.000 11.0 0.225 16 1.8 10 2607.896 2603.672 38.399 4.22 19.33 1.86

2605.068

JCT5 TAP5 2585.670 2585.670 10.000 11.0 0.225 20 2.3 10 2605.068 2603.598 13.367 1.47 17.93 1.21

2601.873

JCT6 TAP6 2582.700 2582.700 10.000 11.0 0.225 20 2.3 10 2601.873 2600.403 13.367 1.47 17.70 1.21

Pipe length (m)

01-May-2008

Pipe L factor1.10

Gravity Water Supply Pipe Network Design by Hazen-Williams MethodUnited Nations Human Settlements Programme (UN-HABITAT), Afghanistan

Residual head @ Stn 2 (m) Remarks

Reach Name Elevation (m)Design flow l/s

HGL(m)Pipe Specifications

Velocity (m/s)

Figure 9.11: Pipe Design as per Example 9.5 by Iranian Standard & Hazen Williams Method.


63

Date 22-Jun-2008Spreadsheet Developed by: Mr. Pushpa Chitrakar, Engineering Advisor, UNHABITAT, Afghanistan. Revision 2007.08Project Sayed Baba MHP Surveyed by: Pipe Combination (Xm) F large pipe (FS) 0.930 F small pipe (FL) 5.100Location Saighan, Bamyan Checked by: Σ Desired head loss 34.68 HGL at the first station 2601.520 Small dia pipe length (X) 614CDC/CCDC Sayed Baba MHP Instrument used: Large pipe 32 III Total pipe length L (m) 975 Big dia pipe length (Y) 361

Pipe L factor 1.10 Small pipe 25 IV Designed Discharge (l/s) 0.225 HGL at the joint 2595.808Pipe length Frictional head loss

station 1 station 2 Station 1 Station 2 ground design diameter class/type station 1 station 2factor (F)

(%) total (m)

SRC1 Combination 1 2666.775 2658.634 255.00 280.5 0.924 63 III 2666.775 2665.586 0.424 1.19 6.95 abc

Combination 1 RVT1 2658.634 2630.000 1745.00 1919.5 0.924 50 III 2665.586 2640.010 1.332 25.58 10.01 abd

RVT1 JCT1 2630.000 2586.190 300.00 330.0 1.575 50 III 2630.000 2618.698 3.425 11.30 32.51

JCT1 JCT2 2586.190 2589.850 174.00 191.4 1.350 50 III 2618.698 2613.702 2.610 5.00 23.85

JCT2 JCT3 2589.850 2586.760 222.00 244.2 1.125 50 III 2613.702 2609.087 1.890 4.62 22.33

JCT3 JCT4 2586.760 2584.340 88.00 96.8 0.900 50 III 2609.087 2607.857 1.270 1.23 23.52

JCT4 JCT5 2584.340 2585.670 357.00 392.7 0.675 50 III 2607.857 2604.814 0.775 3.04 19.14

JCT5 JCT6 2585.670 2582.700 285.00 313.5 0.450 40 III 2604.814 2601.522 1.050 3.29 18.82

JCT6 Combination 2 2582.700 2595.808 329.00 361.9 0.225 32 III 2601.522 2598.156 0.930 3.37 2.35

Combination 2 TAP07 2595.808 2551.840 558.00 613.8 0.225 25 IV 2598.156 2566.853 5.100 31.30 15.01

2618.698

JCT1 TAP1 2586.190 2586.190 95.000 104.5 0.225 20 IV 2618.698 2602.479 15.520 16.22 16.29

2613.702

JCT2 TAP2 2589.850 2588.820 10.000 11.0 0.225 16 IV 2613.702 2607.769 53.940 5.93 18.95

2609.087

JCT3 TAP3 2586.760 2586.760 10.000 11.0 0.225 16 IV 2609.087 2603.153 53.940 5.93 16.39

2607.857

JCT4 TAP4 2584.340 2584.340 10.000 11.0 0.225 16 IV 2607.857 2601.924 53.940 5.93 17.58

2604.814

JCT5 TAP5 2585.670 2585.670 10.000 11.0 0.225 20 IV 2604.814 2603.107 15.520 1.71 17.44

2601.522

JCT6 TAP6 2582.700 2582.700 10.000 11.0 0.225 20 IV 2601.522 2599.815 15.520 1.71 17.11

Gravity Water Supply Pipe Network Design by Tabulated MethodUnited Nations Human Settlements Programme (UN-HABITAT), Afghanistan

Residual head @ Stn 2 (m) Remarks

Reach Name Elevation (m)Design flow l/s

HGL(m)Pipe dia & class/type

Figure 9.12: Pipe Design as per Example 9.5 by Indian Standard & Tabulated Method.


64

DATA SHEETS AND FORMATS

HDPE PIPE SPECIFICATIONS 1. PolyPark HDPE, Iran

2. Herat Polyethylene Company Pipe Specifications, Afghanistan

3. Royal PVC (Pvt) Limited, Pakistan

4. Samnan Pipes, Iran

HEAD LOSS FACTOR TABLES 1. Frictional Headloss Factors for GI (Indian Standards)

2. Friction Factors for HDPE pipes (Indian Standards)

3. Friction Factors for Polypark HDPE pipes (Iranian Standards)

WHO’S DRINKING WATER STANDARDS 1993

FORMATS

1. Abney Level Observation Book

2. Discharge Measurement Using conductivity Meter

3. Level Observation Book

4. Stadia Observation Book

5. Pipe Design Format


65

EN 1555 - EN 12201DIN8074 - DIN8075

SF1.25 PN/BR

SF1.6 PN/BR

SF2.0 PN/BR

SF1.25 PN/BR

SF1.6 PN/BR

SF2.0 PN/BR

SF1.25 PN/BR

SF1.6 PN/BR

SF2.0 PN/BR

OD(mm) t (mm) kg/m t kg/m t kg/m t kg/m t kg/m t kg/m t kg/m t kg/m t kg/m t kg/m t kg/m t kg/m t kg/m t kg/m1 16 - - - - - - - - - - - - - - - - - - - - 1.80 0.084 2.20 0.099 2.70 0.115 3.30 0.133

2 20 - - - - - - - - - - - - - - - - 1.80 0.107 1.9* 0.1121 2.30 0.133 2.80 0.154 3.40 0.180 4.10 0.207

3 25 - - - - - - - - - - - - - - 1.80 0.137 1.90 0.144 2.3* 0.1712 2.80 0.20 3.50 0.24 4.20 0.278 5.10 0.32

4 32 - - - - - - - - - - - - 1.80 0.179 1.90 0.187 2.40 0.232 2.9* 0.2723 3.60 0.327 4.40 0.386 5.40 0.454 6.50 0.52

5 40 - - - - - - 1.8 0.227 1.90 0.238 1.90 0.239 2.30 0.285 2.40 0.295 3.00 0.356 3.70 0.43 4.50 0.509 5.50 0.60 6.70 0.701 8.10 0.809

6 50 - - - - 1.80 0.287 2.0 0.314 2.30 0.361 2.40 0.374 2.90 0.44 3.00 0.453 3.70 0.549 4.60 0.666 5.60 0.788 6.90 0.936 8.30 1.09 10.10 1.26

7 63 - - 1.80 0.364 2.00 0.399 2.5 0.494 2.90 0.563 3.00 0.580 3.60 0.688 3.80 0.721 4.70 0.873 5.80 1.05 7.10 1.26 8.60 1.47 10.50 1.73 12.70 1.99

8 75 1.80 0.436 1.90 0.475 2.30 0.551 2.9 0.675 3.50 0.807 3.60 0.828 4.30 0.976 4.50 1.02 5.60 1.24 6.80 1.47 8.40 1.76 10.30 2.09 12.50 2.44 15.10 2.82

9 90 1.80 0.525 2.20 0.643 2.80 0.791 3.5 0.978 4.10 1.14 4.30 1.18 5.10 1.39 5.40 1.46 6.70 1.77 8.20 2.12 10.10 2.54 12.30 3.00 15.00 3.51 18.10 4.05

10 110 2.20 0.785 2.70 0.943 3.40 1.17 4.2 1.43 5.00 1.67 5.30 1.77 6.30 2.08 6.60 2.17 8.10 2.62 10.00 3.14 12.30 3.78 15.10 4.49 18.30 5.24 22.10 6.04

11 125 2.50 1.00 3.10 1.23 3.90 1.51 4.8 1.84 5.70 2.16 6.00 2.27 7.10 2.66 7.40 2.76 9.20 3.37 11.40 4.08 14.00 4.87 17.10 5.77 20.80 6.75 25.10 7.79

12 140 2.80 1.25 3.50 1.54 4.30 1.88 5.4 2.32 6.40 2.72 6.70 2.83 8.00 3.34 8.30 3.46 10.30 4.22 12.70 5.08 15.70 6.11 19.20 7.25 23.30 8.47 28.10 9.76

13 160 3.20 1.36 4.00 2.00 4.90 2.42 6.2 3.04 7.30 3.54 7.70 3.72 9.10 4.35 9.50 4.52 11.80 5.50 14.60 6.67 17.90 7.96 21.90 9.44 26.60 11.00 32.10 12.70

14 180 3.60 2.05 4.40 2.49 5.50 3.07 6.9 3.79 8.20 4.47 8.60 4.67 10.20 5.48 10.70 5.71 13.30 6.98 16.40 8.42 20.10 10.10 24.60 11.9 29.90 14.00 36.10 16.10

15 200 3.90 4.46 4.90 3.05 6.20 3.84 7.7 4.69 9.10 5.51 9.60 5.78 11.40 6.79 11.90 7.05 14.70 8.56 18.20 10.4 22.40 12.40 27.40 14.8 33.20 17.20 40.10 19.90

16 225 4.40 3.12 5.50 3.86 6.90 4.77 8.6 5.89 10.30 7.00 10.8 7.30 12.80 8.55 13.40 8.93 16.60 10.90 20.50 13.1 25.20 15.80 30.80 18.6 37.40 21.80 45.10 25.20

17 250 4.90 3.83 6.20 4.83 7.70 5.92 9.6 7.30 11.40 8.59 11.9 8.93 14.20 10.60 14.80 11.00 18.40 13.40 22.70 16.2 27.20 19.40 34.20 23.0 41.60 27.00 50.10 31.10

18 280 5.50 4.83 6.90 5.98 8.60 7.40 10.7 9.10 12.80 10.80 13.4 11.30 15.90 13.20 16.60 13.70 20.60 16.80 25.40 20.3 31.10 24.30 38.30 28.9 46.50 33.80 56.20 39.00

19 315 6.20 6.12 7.70 7.52 9.70 9.37 12.1 11.60 14.40 13.60 15.0 14.20 17.90 16.70 18.70 17.40 23.20 21.20 28.60 25.6 35.20 30.80 43.10 36.5 52.30 42.70 63.20 49.30

20 355 7.00 7.73 8.70 9.55 10.90 11.80 13.6 14.60 16.20 17.30 16.9 18.00 20.10 21.20 21.10 22.10 26.10 26.90 32.20 32.5 39.40 39.10 48.50 46.3 59.00 54.30 - -

21 400 7.90 9.82 9.80 12.10 12.30 15.10 15.3 18.60 18.20 21.90 19.1 22.90 22.70 26.90 23.70 28.00 29.40 34.10 36.30 41.3 44.70 49.60 54.70 58.8 66.50 68.90 - -

22 450 8.80 12.30 11.00 15.30 13.80 19.00 17.2 23.50 20.50 27.70 21.5 28.90 25.50 34.00 26.70 35.40 33.10 43.20 40.90 52.3 50.30 62.70 61.50 74.4 - - - -

23 500 9.80 15.20 12.30 19.00 15.30 23.40 19.1 28.90 22.80 34.20 23.9 35.70 28.40 42.00 29.70 43.80 36.80 53.30 45.40 64.5 55.80 77.30 68.30 91.8 - - - -

24 560 11.00 19.10 13.70 23.60 17.20 29.40 21.4 36.20 25.50 42.80 26.7 44.70 31.70 52.50 33.20 54.80 41.20 66.90 50.80 80.8 62.50 97.00 - - - - - -

* 3MM/EN1555: 1-0.16 (Kg/m) 2- 0.210 (Kg/m) 3-0.275 (Kg/m) SDR: (Standard Dimention Ratio)=d/s SF:(Safty Factor) PN:(Pressure Nominal) Series=1/2(d/s-1)

M NI J K LE F G HA B C D

21.61.2

2.5

25

43.12.5

54

3.2

6.354

31.23.1 5 6 6.1 7.9 10 12.5 15.3 20

403.9 6.2 7.5 7.8 9.9 12.5 15.6 19.2 25

20

5 8 9.6 10 12.5 16 20 25 32

252.5 4 4.8 5 6.3 8 10 12.3 16

323.1 5 6 6.2 7.9 10 12.5 15.3 20

15.7

4 6.3 7.5 8 10 12.5 16 20 25

19.62 3.1 3.7 3.9 5 6.3 7.8 10 12.5

19.9 24.93.9 4.7 4.9 6.2 7.8 9.8 12.1 15.7

7.55.9

2

هدردنتسا (IGS) ناریازاگ یلم تکرشو (ISIRA)ناریا یلم یا

6 6.3 8 10 12.4 15.9

3.22.5

21.6

217 13.6 11 9 7.4 6 5

5 4 3.2 2.58.317.6

8 6.310.5 1022 21

1633

12.526

2551

2041

2

2.53.73

6

3.22.4

4.73.8

4.8

PE-100

2.53.14

3.22.5

4.7

PolyPark HDPE Pipes according to international standards Iranian National Standards and National Iranian Gas Co.

PE-80

PE-63

SeriesSDR

21.6

5


66

Herat Polyethylene Company Pipe Specifications (Afghanistan) PE 100PE80PE63

Dia (mm) t (mm) kg/m t (mm) kg/m t (mm) kg/m t (mm) kg/m t (mm) kg/m t (mm) kg/m t (mm) kg/m t (mm) kg/m t (mm) kg/m t (mm) kg/m t (mm) kg/m t (mm) kg/m t (mm) kg/m t (mm) kg/m10 1.8 0.048 2.0 0.05212 1.8 0.060 2.0 0.064 2.4 0.07416 1.8 0.084 2.2 0.099 2.7 0.115 3.3 0.13320 1.8 0.107 1.9 0.112 2.3 0.133 2.8 0.154 3.4 0.180 4.1 0.27025 1.8 0.137 1.9 0.144 2.3 0.171 2.8 0.200 3.5 0.240 4.2 0.278 5.1 0.32032 1.8 0.179 1.9 0.187 2.4 0.232 2.9 0.272 3.2 0.327 4.4 0.386 5.4 0.454 6.5 0.52040 1.8 0.227 1.9 0.238 1.9 0.239 2.0 0.285 2.4 0.295 3.0 0.356 3.7 0.430 4.5 0.509 5.5 0.600 6.7 0.701 8.1 0.80950 1.8 0.287 2.0 0.314 2.3 0.361 2.4 0.374 2.9 0.440 3.0 0.453 3.7 0.549 4.6 0.666 5.6 0.788 6.9 0.936 8.3 1.090 10.1 1.26063 1.8 0.364 2.0 0.399 2.5 0.494 2.9 0.563 3.0 0.580 3.6 0.688 3.8 0.721 4.7 0.873 5.8 1.050 7.1 1.260 8.6 1.470 10.5 1.730 12.7 1.99075 1.8 0.436 1.9 0.457 2.3 0.551 2.9 0.675 3.5 0.807 3.6 0.828 4.3 0.976 4.5 1.020 5.6 1.240 6.8 1.470 8.4 1.760 10.3 2.090 12.5 2.440 15.1 2.82090 1.8 0.525 2.2 0.643 2.8 0.791 3.5 0.978 4.1 1.140 4.3 1.180 5.1 1.390 5.4 1.460 6.7 1.770 8.2 2.120 10.1 2.540 12.3 3.000 15.0 3.510 18.1 4.050

110 2.2 0.706 2.7 0.943 3.4 1.170 4.2 1.430 5.0 1.670 5.3 1.770 6.3 2.080 6.6 2.170 8.1 2.620 10.0 3.140 12.3 3.780 15.1 4.490 18.3 5.240 22.1 6.040125 2.5 1.000 3.1 1.230 3.9 1.510 4.8 1.840 5.7 2.160 6.0 2.270 7.1 2.660 7.4 2.760 9.2 3.370 11.4 4.080 14.0 4.870 17.1 5.770 20.8 6.750 25.1 7.790140 2.8 1.250 3.5 1.540 4.3 1.880 5.4 2.320 6.4 2.720 6.7 2.830 8.0 3.340 8.3 3.460 10.3 4.220 12.7 5.080 15.7 6.110 19.2 7.250 20.3 8.470 28.1 9.750160 3.2 1.530 4.0 2.000 4.9 2.420 6.2 3.040 7.3 3.540 7.7 3.720 9.1 4.350 9.5 4.520 11.8 5.500 14.6 6.670 17.9 7.960 21.9 9.440 20.6 11.000 32.1 12.700180 3.6 2.500 4.4 2.400 5.5 3.070 6.9 3.790 8.2 4.470 8.6 4.670 10.2 5.480 10.7 5.710 13.3 6.980 16.4 8.420 20.1 10.100 24.6 11.900 29.9 14.000 36.1 16.100200 3.9 2.460 4.9 3.500 6.2 3.840 7.7 4.690 9.1 5.510 9.6 5.780 11.4 6.790 11.9 7.050 14.7 8.560 17.2 10.400 22.4 12.400 27.1 14.800 33.2 17.200 40.1 15.900225 4.4 3.120 5.5 3.860 6.9 4.770 8.6 5.890 10.3 7.000 10.8 7.300 12.8 8.550 13.4 8.930 16.6 10.900 20.5 13.100 25.2 15.800 30.8 18.600 37.4 21.800 45.1 25.200250 4.9 3.830 6.2 4.830 7.7 5.920 9.6 7.300 11.4 8.590 11.9 8.930 14.2 10.700 14.8 11.000 18.4 13.400 22.7 16.200 27.9 15.400 34.2 23.000 41.6 27.000 50.1 31.100280 5.5 4.830 6.9 5.980 8.6 7.400 10.7 9.100 12.8 10.800 13.4 11.300 15.9 13.200 16.6 13.700 20.6 16.800 25.4 20.300 31.3 24.300 38.3 28.900 46.5 33.300 56.2 39.000315 6.2 6.120 7.7 7.520 9.7 9.370 12.1 11.600 14.4 13.600 15.0 14.200 17.9 16.700 18.7 17.400 23.2 21.200 28.6 25.600 35.2 30.800 43.1 36.500 52.3 42.700 63.2 49.300355 7.0 7.730 8.7 9.550 10.9 11.800 13.6 14.600 16.2 17.300 16.9 18.000 20.1 21.200 21.1 22.100 26.1 26.900 30.2 32.500 39.7 39.100 48.5 46.500 59.0 54.800400 7.9 9.820 9.8 12.100 12.3 15.100 15.3 18.600 18.2 21.900 19.1 22.900 22.7 26.900 23.7 28.000 29.4 34.100 36.3 41.300 44.7 49.600 54.7 58.800 66.5 68.900450 8.8 12.300 11.0 15.300 13.8 19.000 17.2 23.500 20.5 27.700 21.5 28.900 25.5 34.000 26.7 35.400 33.1 43.200 40.9 52.300 50.3 62.700 61.5 74.400500 9.8 15.200 13.3 19.000 15.3 23.400 19.1 28.900 22.8 34.200 23.9 35.700 28.8 42.000 29.7 43.800 36.8 53.300 45.4 64.500 55.8 77.300 88.3 91.800560 11.0 19.100 13.7 23.600 17.2 29.400 21.4 36.200 25.5 42.800 26.7 44.700 31.7 52.500 33.2 54.800 41.2 66.900 50.8 80.800 62.5 97.000630 12.3 24.000 15.4 29.900 19.3 37.100 24.1 45.900 28.7 54.100 30.0 56.400 35.7 66.700 37.4 69.000 46.3 84.600 57.2 102.000

6 513.6 11 9 7.42.5 2

51 41 33 26 22 21 17.6 176.3 5 4 3.2

PN 20 N25 20 16 12.5 10.5 10 8.3 8

PN 8 PN 10 PN 12.6 PN 16PN 25.8 PN 32

PN PN 2.5 PN 3.2 PN 4 PN 4.8 PN 5 PN 6 PN 6.3PN 10 PN 12.5 PN 16 PN 20

PN 32 PN 40PN 2.5 PN 3.2 PN 4 PN 5 PN 6 PN 6.4 PN 7.7 PN 8

PN 12.7 PN 16 PN 20 PN 25PN 7.8 PN 8 PN 9.6 PN 10PN 3.2 PN 4 PN 5 PN 6.4


67

Royal PVC (Pvt) Limited (Pakistan) Specifications for PE 100 Pipes STANDARD DIN 8074

PNSDR

Min Max Min Max Min Max Min Max20 1.8 2.2 1.9 2.3 2.2 3.325 1.8 2.2 2.3 2.8 3.5 4.132 1.8 2.2 1.9 2.3 3 3.6 4.5 5.240 1.8 2.2 2.3 2.8 3.7 4.4 5.6 6.450 2 2.5 2.9 3.4 4.6 5.3 6.9 7.863 2.5 3 3.6 4.1 5.8 6.6 8.7 9.875 2.9 3.4 4.3 5 6.9 7.8 10.4 11.790 3.5 4.2 5.1 5.9 8.2 9.3 12.5 14

110 4.3 5 6.3 7.2 10 11.3 15.2 17125 4.9 5.6 7.1 8.1 11.4 12.8 17.3 19.3140 5.4 6.2 8 9.1 12.8 14.3 19.4 21.6160 6.2 7.1 9.1 9.3 14.6 16.3 22.1 24.5180 7 8 10.2 11.5 16.4 18.3 24.9 27.6200 7.5 8.7 11.4 12.8 18.2 20.3 27.6 30.6

Thickness (mm) Thickness (mm)Dia (mm)

10 1617.6 11 7.25

Thickness (mm)

426

6

Thickness (mm)


68

Samnan Polyethylene Pipes (Iran) PE 63

t (mm) kg/m t (mm) kg/m t (mm) kg/m t (mm) kg/m t (mm) kg/m20 2 0.11725 2 0.15 2.3 0.17132 2 0.196 3 0.27940 2 0.248 2.3 0.285 3.7 0.4350 1.8 0.299 2 0.314 2.9 0.44 4.6 0.66663 1.8 0.380 2 0.399 2.5 0.494 3.6 0.688 5.8 1.05075 2 0.478 2.4 0.572 2.9 0.675 4.3 0.976 6.9 1.4890 2.2 0.639 2.8 0.791 3.5 0.978 5.1 1.39 8.2 2.12

110 2.7 0.941 3.5 1.2 4.3 1.46 6.3 2.08 10 3.14125 3.1 1.23 3.9 1.51 4.9 1.88 7.1 2.66 11.4 4.08140 3.5 1.54 4.4 1.92 5.4 2.32 8 3.34 12.8 5.11160 3.9 1.95 5 2.47 6.2 3.04 9.1 4.35 14.6 6.67180 4.4 2.48 5.6 3.12 7 3.84 10.2 5.48 16.4 8.42200 4.9 3.05 6.2 3.84 7.7 4.69 11.4 6.79 18.2 10.4225 5.5 3.06 7 4.84 8.7 5.96 12.8 8.55 20.5 13.1250 6.1 4.76 7.8 5.99 9.7 7.37 14.2 10.6 22.8 16.2280 6.9 5.98 8.7 7.47 10.8 9.18 15.9 13.2 25.5 20.3315 7.7 7.51 9.8 9.45 12.2 11.7 17.9 16.7 28.7 25.7355 8.7 9.54 11.1 12.1 13.7 14.7 20.1 21.2 32.3 32.6400 9.8 12.1 12.4 15.2 15.4 18.7 22.7 26.9 36.4 41.4450 11 15.2 14 19.2 17.4 23.7 25.5 34 41 52.4

PN 10Dia (mm)

PN 2.5 PN 3.2 PN 4 PN 6


69

Samnan Polyethelene Pipes (Iran)

PE 80

t (mm) kg/m t (mm) kg/m t (mm) kg/m t (mm) kg/m t (mm) kg/m t (mm) kg/m101216 1.8 0.08420 1.8 0.107 2.3 0.13325 1.9 0.144 2.8 0.20032 2.4 0.232 3.6 0.32740 1.9 0.238 3.0 0.356 4.5 0.50950 1.8 0.287 2.3 0.361 3.7 0.549 5.6 0.78863 1.8 0.364 2.0 0.399 2.9 0.563 4.7 0.873 7.1 1.26075 1.8 0.436 1.9 0.457 2.3 0.551 3.5 0.807 5.6 1.240 8.4 1.76090 1.8 0.525 2.2 0.643 2.8 0.791 4.1 1.140 6.7 1.770 10.1 2.540

110 2.2 0.786 2.7 0.943 3.4 1.170 5.0 1.670 8.1 2.620 12.3 3.780125 2.5 1.000 3.1 1.230 3.9 1.510 5.7 2.160 9.2 3.370 14.0 4.870140 2.8 1.250 3.5 1.540 4.3 1.880 6.4 2.720 10.3 4.220 15.7 6.110160 3.2 1.630 4.0 2.000 4.9 2.420 7.3 3.540 11.8 5.500 17.9 7.960180 3.6 2.050 4.4 2.490 5.5 3.070 8.2 4.470 13.3 6.980 20.1 10.100200 3.9 2.460 4.9 3.050 6.2 3.840 9.1 5.510 14.7 8.560 22.4 12.400225 4.4 3.120 5.5 3.860 6.9 4.770 10.3 7.000 16.6 10.900 25.2 15.800250 4.9 3.830 6.2 4.830 7.7 5.920 11.4 8.590 18.4 13.400 27.9 19.400280 5.5 4.830 6.9 5.980 8.6 7.400 12.8 10.800 20.6 16.800 31.3 24.300315 6.2 6.120 7.7 7.520 9.7 9.370 14.4 13.600 23.2 21.200 35.2 30.800355 7.0 7.730 8.7 9.500 10.9 11.800 16.2 17.300 26.1 26.900 39.7 39.100400 7.9 9.820 9.8 12.100 12.3 15.100 18.2 21.900 29.4 34.100 44.7 49.600450 8.8 12.300 11.0 15.300 13.8 19.000 20.5 27.700 33.1 43.200 50.3 62.700500 9.8 15.200 12.3 19.000 15.3 23.400 22.8 34.200 36.8 53.300 55.8 77.300560 11.0 19.100 13.7 23.600 17.2 29.400 23.5 42.800 41.2 66.900 62.5 97.000630 12.3 24.000 15.4 29.900 19.3 37.100 28.7 54.100 46.3 84.600710 13.9 30.500 17.4 38.000 21.8 47.200 32.3 68.700 52.2 107.000800 15.7 38.800 19.6 48.100 24.5 59.700 36.4 87.200 58.8 136.000900 17.6 48.900 22.0 60.900 27.6 75.600 41.0 110.000 66.1 172.000

1000 19.6 60.500 24.5 75.200 30.6 93.100 45.5 136.000

PN 16PN 10Dia (mm)

PN 2.5 PN 3.2 PN 4 PN 6


70

Samnan Polyethelene Pipes (Iran)

PE 100 DIN 8074 WITH SF = 1.6

t (mm) kg/m t (mm) kg/m t (mm) kg/m t (mm) kg/m t (mm) kg/m t (mm) kg/m t (mm) kg/m t (mm) kg/m t (mm) kg/m t (mm) kg/m t (mm) kg/m t (mm) kg/m101216 1.8 0.084 2.2 0.09920 1.8 0.107 1.9 0.112 2.3 0.133 2.8 0.15425 1.8 0.137 1.9 0.144 2.3 0.17 2.8 0.2 3.5 0.2432 1.8 0.179 1.9 0.187 2.4 0.232 2.9 0.272 3.6 0.327 4.4 0.38640 1.8 0.227 1.9 0.238 1.9 0.239 2.3 0.285 2.4 0.295 3 0.355 3.7 0.43 4.5 0.509 5.5 0.650 1.8 0.287 2 0.314 2.3 0.361 2.4 0.374 2.9 0.44 3 0.483 3.7 0.549 4.6 0.666 5.6 0.788 6.9 0.93663 1.8 0.364 2 0.399 2.5 0.494 2.9 0.563 3 0.58 3.6 0.688 3.8 0.71 4.7 0.873 5.8 1.05 7.1 1.26 8.6 1.4775 1.8 0.436 1.9 0.457 2.3 0.551 2.9 0.675 3.5 0.807 3.6 0.828 4.3 0.976 4.5 1.02 5.6 1.24 6.8 1.47 8.4 1.76 10.3 2.0990 1.8 0.525 2.2 0.43 2.5 0.791 3.5 0.978 4.1 1.14 4.3 1.18 5.1 1.39 5.4 1.46 6.7 1.77 8.2 2.12 10.1 2.54 12.3 3

110 2.2 0.785 2.7 0.943 3.4 1.17 4.2 1.43 5 1.67 5.3 1.77 6.3 2.08 6.6 2.17 8.1 2.62 10 3.14 12.3 3.78 15.1 4.49125 2.5 1 3.1 1.23 3.9 1.51 4.8 1.84 5.7 2.16 6 2.27 7.1 2.66 7.4 2.76 9.2 3.37 11.4 4.08 14 4.87 17.1 6.77140 2.8 1.25 3.8 1.54 4.3 1.88 5.4 2.32 6.4 2.72 6.7 2.84 8 3.34 8.3 3.46 10.3 4.22 12.7 5.08 15.7 6.11 19.2 7.25160 3.2 1.63 4 2 4.9 2.42 6.2 3.04 7.3 3.54 7.7 3.72 9.1 4.35 9.5 4.52 11.8 5.5 14.6 6.67 17.9 7.96 21.9 9.44180 3.6 2.03 4.4 2.49 5.5 3.07 6.9 3.79 8.2 4.47 8.6 4.67 10.2 5.45 10.7 5.71 13.3 6.98 16.4 8.42 20.1 10.1 24.6 11.9200 3.9 2.46 4.9 3.05 6.2 3.84 7.7 4.69 9.1 6.51 9.6 5.76 11.4 6.79 11.9 7.05 14.7 8.56 18.2 10.4 23.4 12.4 27.4 14.8225 4.4 3.12 5.5 3.86 6.9 4.77 8.6 6.89 10.3 7 10.8 7.3 12.8 8.55 13.4 8.93 16.6 10.9 20.5 13.1 25.2 16.8 30.8 18.6250 4.9 3.83 6.2 4.83 7.7 5.92 9.6 7.3 11.4 8.59 11.9 8.93 14.2 10.6 14.8 11 18.4 13.4 22.7 16.3 27.9 19.4 34.2 23280 5.5 4.83 6.9 5.98 8.6 7.4 10.7 9.1 12.8 10.5 13.4 11.3 15.9 13.2 16.6 13.7 20.6 16.8 25.4 20.3 31.3 24.3 38.3 28.9315 6.2 6.12 7.7 7.52 9.7 9.37 12.1 11.6 14.4 13.5 15 14.2 17.9 16.7 18.7 17.4 23.2 21.2 28.6 25.6 35.2 30.8 43.1 36.5355 7 7.73 8.7 9.53 10.9 11.8 13.6 14.6 16.2 17.3 16.9 15 20.1 21.2 21.1 22.1 26.1 26.9 32.2 32.5 39.7 39.1 48.5 46.3400 7.9 9.82 9.8 12.1 12.3 15.1 15.3 18.6 18.2 21.9 19..1 22.9 22.7 26.9 23.7 28 29.4 34.1 36.3 41.3 44.7 49.6 54.7 58.8450 8.8 12.3 11 15.3 13.8 19 17.2 23.5 20.5 27.7 21.5 28.9 25.5 34 26.7 35.4 33.1 43.2 40.9 52.3 50.3 62.7 61.3 74.4500 9.4 15.2 12.3 19 16.3 23.4 19.1 28.9 22.5 34.2 23.9 35.7 28.4 43 29.7 43.8 36.8 53.3 45.4 64.5 55.8 77.3 68.3 91.8560 11 19.1 13.7 23.6 17.2 29.4 21.4 30.2 25.5 42.8 26.7 44.7 31.7 52.5 32.2 54.8 41.2 66.9 50.8 80.5 62.5 97630 12.3 24 15.4 29.9 19.3 37.1 24.1 45.9 28.7 52.1 30 56.4 35.7 66.5 37.4 69.4 46.3 84.6 57.2 102710 13.9 30.5 17.4 38 21.8 47.2 27.2 58.4 32.3 68.7 33.9 71.5 40.2 84.4 42.1 88.1 52.2 107 64.8 130800 15.7 38.8 19.4 48.1 24.8 59.7 30.6 73.9 36.4 57.2 38.1 91.1 45.3 107 47.4 112 58.8 136

PN 12.5 PN 15.6 PN 19.2PN 6.2 PN 7.5 PN 7.8 PN 9.9PN 5.9Dia (mm)

PN 2.5 PN 3.1 PN 3.9 PN 5


71

GI frictional headloss factorsDia => 1/2"GI 3/4"GI 1"GI 1 1/4"GI 1 1/2"GI 2"GI 2 1/2"GI 3"GI 4"GIFlow (l/s) 12.7 mm 19.1 mm 25.4 mm 31.8 mm 38.1 mm 50.8 mm 63.5 mm 76.2 mm 101.6 mm

0.100 V LOW V LOW V LOW V LOW V LOW V LOW V LOW V LOW V LOW0.120 8.980 V LOW V LOW V LOW V LOW V LOW V LOW V LOW V LOW0.140 12.180 V LOW V LOW V LOW V LOW V LOW V LOW V LOW V LOW0.160 15.860 V LOW V LOW V LOW V LOW V LOW V LOW V LOW V LOW0.180 20.040 V LOW V LOW V LOW V LOW V LOW V LOW V LOW V LOW0.200 24.700 V LOW V LOW V LOW V LOW V LOW V LOW V LOW V LOW0.220 29.850 6.660 V LOW V LOW V LOW V LOW V LOW V LOW V LOW0.240 35.480 7.910 V LOW V LOW V LOW V LOW V LOW V LOW V LOW0.260 41.600 9.270 V LOW V LOW V LOW V LOW V LOW V LOW V LOW0.280 48.210 10.730 V LOW V LOW V LOW V LOW V LOW V LOW V LOW0.300 55.310 12.310 V LOW V LOW V LOW V LOW V LOW V LOW V LOW0.320 62.890 13.990 V LOW V LOW V LOW V LOW V LOW V LOW V LOW0.340 70.960 15.770 4.930 V LOW V LOW V LOW V LOW V LOW V LOW0.360 79.510 17.670 5.520 V LOW V LOW V LOW V LOW V LOW V LOW0.380 88.550 19.670 6.140 V LOW V LOW V LOW V LOW V LOW V LOW0.400 98.080 21.780 6.800 V LOW V LOW V LOW V LOW V LOW V LOW0.420 V HIGH 24.000 7.490 V LOW V LOW V LOW V LOW V LOW V LOW0.440 V HIGH 26.330 8.210 V LOW V LOW V LOW V LOW V LOW V LOW0.460 V HIGH 28.760 8.970 V LOW V LOW V LOW V LOW V LOW V LOW0.480 V HIGH 31.300 9.760 V LOW V LOW V LOW V LOW V LOW V LOW0.500 V HIGH 33.950 10.580 V LOW V LOW V LOW V LOW V LOW V LOW0.550 V HIGH 41.040 12.790 3.530 V LOW V LOW V LOW V LOW V LOW0.600 V HIGH 48.800 15.200 4.190 V LOW V LOW V LOW V LOW V LOW0.650 V HIGH 57.240 17.820 4.910 V LOW V LOW V LOW V LOW V LOW0.700 V HIGH 66.340 20.650 5.690 V LOW V LOW V LOW V LOW V LOW0.750 V HIGH 76.120 23.680 6.520 V LOW V LOW V LOW V LOW V LOW0.800 V HIGH 86.570 26.930 7.420 V LOW V LOW V LOW V LOW V LOW0.850 V HIGH 97.690 30.380 8.360 2.610 V LOW V LOW V LOW V LOW0.900 V HIGH V HIGH 34.040 9.370 2.930 V LOW V LOW V LOW V LOW1.000 V HIGH V HIGH 41.990 11.550 3.610 V LOW V LOW V LOW V LOW1.100 V HIGH V HIGH 50.770 13.960 4.350 V LOW V LOW V LOW V LOW1.200 V HIGH V HIGH 60.380 16.590 5.170 V LOW V LOW V LOW V LOW1.300 V HIGH V HIGH 70.820 19.460 6.060 V LOW V LOW V LOW V LOW1.400 V HIGH V HIGH 82.100 22.550 7.030 2.190 V LOW V LOW V LOW1.500 V HIGH V HIGH 94.210 25.870 8.060 2.520 V LOW V LOW V LOW1.600 V HIGH V HIGH V HIGH 29.420 9.160 2.860 V LOW V LOW V LOW1.700 V HIGH V HIGH V HIGH 33.190 10.330 3.220 V LOW V LOW V LOW1.800 V HIGH V HIGH V HIGH 37.200 11.580 3.610 V LOW V LOW V LOW1.900 V HIGH V HIGH V HIGH 41.430 12.890 4.020 V LOW V LOW V LOW2.000 V HIGH V HIGH V HIGH 45.890 14.270 4.450 V LOW V LOW V LOW2.100 V HIGH V HIGH V HIGH 50.690 15.760 4.915 V LOW V LOW V LOW2.200 V HIGH V HIGH V HIGH 55.490 17.250 5.380 V LOW V LOW V LOW2.300 V HIGH V HIGH V HIGH 60.745 18.885 5.885 1.500 V LOW V LOW2.400 V HIGH V HIGH V HIGH 66.000 20.520 6.390 1.630 V LOW V LOW2.500 V HIGH V HIGH V HIGH 71.710 22.290 6.940 1.760 V LOW V LOW2.600 V HIGH V HIGH V HIGH V HIGH 24.060 7.490 1.910 V LOW V LOW2.700 V HIGH V HIGH V HIGH V HIGH 25.975 8.085 2.050 V LOW V LOW2.800 V HIGH V HIGH V HIGH V HIGH 27.890 8.680 2.210 V LOW V LOW2.900 V HIGH V HIGH V HIGH V HIGH 29.945 9.320 2.370 V LOW V LOW3.000 V HIGH V HIGH V HIGH V HIGH 32.000 9.960 2.530 V LOW V LOW3.200 V HIGH V HIGH V HIGH V HIGH 36.400 11.320 2.890 0.980 V LOW3.400 V HIGH V HIGH V HIGH V HIGH 41.070 12.770 3.250 1.100 V LOW3.500 V HIGH V HIGH V HIGH V HIGH 43.550 13.540 3.430 1.160 V LOW3.600 V HIGH V HIGH V HIGH V HIGH 46.030 14.310 3.640 1.232 V LOW3.800 V HIGH V HIGH V HIGH V HIGH V HIGH 15.940 4.060 1.376 V LOW4.000 V HIGH V HIGH V HIGH V HIGH V HIGH 17.650 4.480 1.520 V LOW4.500 V HIGH V HIGH V HIGH V HIGH V HIGH 22.320 5.660 1.910 V LOW5.000 V HIGH V HIGH V HIGH V HIGH V HIGH 27.540 6.980 2.360 V LOW5.500 V HIGH V HIGH V HIGH V HIGH V HIGH 33.300 8.505 2.875 0.9006.000 V HIGH V HIGH V HIGH V HIGH V HIGH 39.610 10.030 3.390 1.0606.500 V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH 11.830 3.995 1.2507.000 V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH 13.630 4.600 1.4407.500 V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH 15.710 5.300 1.6558.000 V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH 17.790 6.000 1.8709.000 V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH 22.500 7.590 2.360

10.000 V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH 27.750 9.360 2.91012.000 V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH 13.460 4.19014.000 V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH 18.300 5.69022.000 V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH 14.000

Note: velocity range (0.3 to 3m/s)


72

Friction Factors for HDPE pipes (Indian Standards) Head loss chart for HDP Pipe(ISI Standard) 2.2 2.55 3.05 3.95 2.55 4.85 3.15 6 3.9 7.6 4.85 3.25 6.85 3.7 5.4

ID (mm) 11.60 14.90 18.90 24.10 26.90 30.30 33.70 38.00 42.20 47.80 53.30 56.50 76.30 102.60 99.20OD (mm) 16 20 25 32 32 40 40 50 50 63 63 63 90 110 110Pressure 10kg/cm2 10kg/cm2 10kg/cm2 10kg/cm2 6kg/cm2 10kg/cm2 6kg/cm2 10kg/cm2 6kg/cm2 10kg/cm2 6kg/cm2 4kg/cm2 6kg/cm2 2.5kg/cm2 4kg/cm2

Flow (l/s) 16IV 20IV 25IV 32IV 32III 40IV 40III 50IV 50III 63IV 63III 63II 90III 110I 110II0.050 V LOW V LOW V LOW VLOW V LOW VLOW VLOW VLOW VLOW VLOW VLOW VLOW VLOW VLOW VLOW0.100 12.60 3.70 1.20 0.40 V LOW V LOW V LOW V LOW V LOW V LOW V LOW VLOW V LOW V LOW V LOW0.110 14.93 4.35 1.50 0.50 0.30 V LOW V LOW V LOW V LOW V LOW V LOW VLOW V LOW V LOW V LOW0.120 17.44 5.07 1.70 0.50 0.30 V LOW V LOW V LOW V LOW V LOW V LOW VLOW V LOW V LOW V LOW0.130 20.12 5.84 2.00 0.60 0.40 V LOW V LOW V LOW V LOW V LOW V LOW VLOW V LOW V LOW V LOW0.140 22.97 6.66 2.20 0.70 0.40 V LOW V LOW V LOW V LOW V LOW V LOW VLOW V LOW V LOW V LOW0.150 26.00 7.53 2.50 0.80 0.50 V LOW V LOW V LOW V LOW V LOW V LOW VLOW V LOW V LOW V LOW0.160 29.19 8.45 2.80 0.90 0.50 V LOW V LOW V LOW V LOW V LOW V LOW VLOW V LOW V LOW V LOW0.170 32.54 9.41 3.10 1.00 0.60 V LOW V LOW V LOW V LOW V LOW V LOW VLOW V LOW V LOW V LOW0.180 36.07 10.42 3.43 1.10 0.60 V LOW V LOW V LOW V LOW V LOW V LOW VLOW V LOW V LOW V LOW0.190 39.75 11.47 3.78 1.20 0.60 V LOW V LOW V LOW V LOW V LOW V LOW VLOW V LOW V LOW V LOW0.200 43.60 12.57 4.14 1.30 0.80 V LOW V LOW V LOW V LOW V LOW V LOW VLOW V LOW V LOW V LOW0.210 47.62 13.72 4.51 1.45 0.85 V LOW V LOW V LOW V LOW V LOW V LOW VLOW V LOW V LOW V LOW0.220 51.79 14.91 4.90 1.60 0.90 0.50 0.30 V LOW V LOW V LOW V LOW VLOW V LOW V LOW V LOW0.225 53.94 15.52 5.10 1.65 0.93 0.53 0.33 V LOW V LOW V LOW V LOW VLOW V LOW V LOW V LOW0.230 56.13 16.14 5.30 1.70 0.95 0.55 0.35 V LOW V LOW V LOW V LOW VLOW V LOW V LOW V LOW0.240 60.63 17.42 5.72 1.80 1.00 0.60 0.40 V LOW V LOW V LOW V LOW VLOW V LOW V LOW V LOW0.250 65.28 18.74 6.15 1.95 1.10 0.65 0.40 V LOW V LOW V LOW V LOW VLOW V LOW V LOW V LOW0.260 70.10 20.11 6.60 2.10 1.20 0.70 0.40 V LOW V LOW V LOW V LOW VLOW V LOW V LOW V LOW0.280 80.20 22.97 7.53 2.40 1.40 0.80 0.50 V LOW V LOW V LOW V LOW VLOW V LOW V LOW V LOW0.300 90.94 26.00 8.51 2.70 1.60 0.90 0.50 V LOW V LOW V LOW V LOW VLOW V LOW V LOW V LOW0.320 102.30 29.21 9.55 3.03 1.80 1.00 0.60 0.30 V LOW V LOW V LOW VLOW V LOW V LOW V LOW0.340 V HIGH 32.58 10.64 3.37 1.92 1.10 0.70 0.40 V LOW V LOW V LOW VLOW V LOW V LOW V LOW0.360 V HIGH 36.12 11.79 3.73 2.12 1.20 0.70 0.40 0.30 V LOW V LOW VLOW V LOW V LOW V LOW0.380 V HIGH 39.83 12.99 4.11 2.33 1.30 0.80 0.50 0.30 V LOW V LOW VLOW V LOW V LOW V LOW0.400 V HIGH 43.71 14.24 4.50 2.56 1.50 0.90 0.50 0.30 V LOW V LOW VLOW V LOW V LOW V LOW0.420 V HIGH 47.75 15.54 4.91 2.79 1.60 1.00 0.50 0.30 V LOW V LOW VLOW V LOW V LOW V LOW0.440 V HIGH 51.95 16.89 5.33 3.03 1.70 1.00 0.60 0.40 V LOW V LOW VLOW V LOW V LOW V LOW0.460 V HIGH 56.33 18.30 5.77 3.28 1.90 1.10 0.60 0.40 V LOW V LOW VLOW V LOW V LOW V LOW0.480 V HIGH 60.86 19.75 6.23 3.53 2.00 1.20 0.70 0.40 V LOW V LOW VLOW V LOW V LOW V LOW0.500 V HIGH 65.56 21.26 6.70 3.80 2.18 1.30 0.70 0.50 V LOW V LOW VLOW V LOW V LOW V LOW0.520 V HIGH 70.42 22.82 7.20 4.08 2.34 1.40 0.80 0.50 V LOW V LOW VLOW V LOW V LOW V LOW0.540 V HIGH 72.80 24.42 7.69 4.36 2.51 1.50 0.80 0.50 V LOW V LOW VLOW V LOW V LOW V LOW0.550 V HIGH 74.85 25.24 7.94 4.50 2.59 1.55 0.85 0.50 V LOW V LOW VLOW V LOW V LOW V LOW0.560 V HIGH 76.90 26.08 8.21 4.65 2.68 1.60 0.90 0.50 V LOW V LOW VLOW V LOW V LOW V LOW0.580 V HIGH 81.00 27.79 8.74 4.96 2.85 1.71 1.00 0.60 V LOW V LOW VLOW V LOW V LOW V LOW0.600 V HIGH 85.00 29.54 9.28 5.26 3.02 1.81 1.00 0.60 0.30 V LOW VLOW V LOW V LOW V LOW0.620 V HIGH 89.10 31.35 9.85 5.58 3.20 1.92 1.10 0.70 0.40 V LOW VLOW V LOW V LOW V LOW0.640 V HIGH V HIGH 33.21 10.42 5.90 3.39 2.03 1.20 0.70 0.40 V LOW VLOW V LOW V LOW V LOW0.650 V HIGH V HIGH 34.16 10.71 6.06 3.48 2.09 1.20 0.70 0.40 V LOW VLOW V LOW V LOW V LOW0.660 V HIGH V HIGH 35.11 11.01 6.23 3.58 2.15 1.20 0.70 0.40 V LOW VLOW V LOW V LOW V LOW0.680 V HIGH V HIGH 37.06 11.62 6.58 3.77 2.26 1.30 0.80 0.40 0.30 VLOW V LOW V LOW V LOW0.700 V HIGH V HIGH 39.07 12.23 6.92 3.97 2.38 1.30 0.80 0.50 0.30 VLOW V LOW V LOW V LOW0.720 V HIGH V HIGH 41.12 12.88 7.28 4.18 2.50 1.40 0.90 0.50 0.30 VLOW V LOW V LOW V LOW0.740 V HIGH V HIGH 43.22 13.53 7.65 4.39 2.63 1.50 0.90 0.50 0.30 VLOW V LOW V LOW V LOW0.750 V HIGH V HIGH 44.30 13.85 7.83 4.49 2.69 1.50 0.90 0.50 0.30 VLOW V LOW V LOW V LOW0.760 V HIGH V HIGH 45.37 14.19 8.02 4.60 2.76 1.50 0.90 0.50 0.30 VLOW V LOW V LOW V LOW0.780 V HIGH V HIGH 47.56 14.87 8.41 4.82 2.89 1.60 1.00 0.50 0.30 VLOW V LOW V LOW V LOW0.800 V HIGH V HIGH 49.81 15.55 8.79 5.04 3.02 1.70 1.02 0.60 0.30 VLOW V LOW V LOW V LOW0.850 V HIGH V HIGH 55.96 17.35 9.80 5.62 3.36 1.91 1.15 0.65 0.35 0.30 V LOW V LOW V LOW0.900 V HIGH V HIGH 62.10 19.23 10.86 6.22 3.73 2.11 1.27 0.70 0.40 0.30 V LOW V LOW V LOW0.950 V HIGH V HIGH V HIGH 21.21 11.97 6.85 4.10 2.32 1.40 0.75 0.45 0.30 V LOW V LOW V LOW1.000 V HIGH V HIGH V HIGH 23.27 13.13 7.51 4.50 2.52 1.52 0.80 0.50 0.40 V LOW V LOW V LOW1.050 V HIGH V HIGH V HIGH 25.42 14.33 8.20 4.90 2.76 1.67 0.90 0.55 0.40 V LOW V LOW V LOW1.100 V HIGH V HIGH V HIGH 27.66 15.59 8.91 5.33 3.01 1.82 1.00 0.60 0.40 V LOW V LOW V LOW1.150 V HIGH V HIGH V HIGH 29.98 16.89 9.65 5.77 3.25 1.96 1.08 0.65 0.50 V LOW V LOW V LOW1.200 V HIGH V HIGH V HIGH 32.39 18.24 10.42 6.22 3.49 2.11 1.16 0.70 0.50 V LOW V LOW V LOW1.250 V HIGH V HIGH V HIGH 34.89 19.64 11.21 6.70 3.77 2.28 1.25 0.75 0.50 V LOW V LOW V LOW1.300 V HIGH V HIGH V HIGH 37.48 21.08 12.03 7.19 4.04 2.44 1.34 0.80 0.60 V LOW V LOW V LOW1.350 V HIGH V HIGH V HIGH 40.15 22.57 12.88 7.69 4.32 2.61 1.43 0.85 0.65 V LOW V LOW V LOW1.400 V HIGH V HIGH V HIGH 41.80 24.11 13.75 8.21 4.59 2.77 1.52 0.90 0.70 V LOW V LOW V LOW1.450 V HIGH V HIGH V HIGH V HIGH 25.70 14.65 8.74 4.90 2.96 1.62 0.96 0.75 V LOW V LOW V LOW1.500 V HIGH V HIGH V HIGH V HIGH 27.33 15.58 9.29 5.22 3.15 1.73 1.02 0.80 V LOW V LOW V LOW1.550 V HIGH V HIGH V HIGH V HIGH 29.01 16.53 9.86 5.53 3.33 1.83 1.08 0.85 V LOW V LOW V LOW1.600 V HIGH V HIGH V HIGH V HIGH 30.74 17.51 10.44 5.84 3.52 1.93 1.14 0.80 V LOW V LOW V LOW1.650 V HIGH V HIGH V HIGH V HIGH 32.51 18.51 11.03 6.18 3.73 2.04 1.21 0.90 V LOW V LOW V LOW1.700 V HIGH V HIGH V HIGH V HIGH 34.33 19.54 11.64 6.53 3.93 2.16 1.28 0.90 V LOW V LOW V LOW1.750 V HIGH V HIGH V HIGH V HIGH V HIGH 20.59 12.27 6.87 4.14 2.27 1.34 1.00 V LOW V LOW V LOW1.800 V HIGH V HIGH V HIGH V HIGH V HIGH 21.68 12.91 7.21 4.34 2.38 1.41 1.05 V LOW V LOW V LOW1.850 V HIGH V HIGH V HIGH V HIGH V HIGH 22.78 13.57 7.59 4.57 2.50 1.48 1.10 V LOW V LOW V LOW1.900 V HIGH V HIGH V HIGH V HIGH V HIGH 23.91 14.24 7.96 4.79 2.63 1.56 1.15 0.30 V LOW V LOW1.950 V HIGH V HIGH V HIGH V HIGH V HIGH 25.07 14.92 8.34 5.02 2.75 1.63 1.20 0.30 V LOW V LOW2.000 V HIGH V HIGH V HIGH V HIGH V HIGH 26.25 15.62 8.71 5.24 2.87 1.70 1.30 0.30 V LOW V LOW2.100 V HIGH V HIGH V HIGH V HIGH V HIGH 28.70 17.06 9.53 5.73 3.14 1.86 1.40 0.30 V LOW V LOW2.200 V HIGH V HIGH V HIGH V HIGH V HIGH 31.24 18.57 10.35 6.22 3.41 2.02 1.50 0.40 V LOW V LOW2.300 V HIGH V HIGH V HIGH V HIGH V HIGH 34.40 20.13 11.23 13.50 3.70 2.19 1.60 0.40 V LOW V LOW2.400 V HIGH V HIGH V HIGH V HIGH V HIGH 37.20 21.75 12.11 7.28 3.98 2.35 1.70 0.40 V LOW V LOW2.500 V HIGH V HIGH V HIGH V HIGH V HIGH 40.10 23.43 13.05 7.84 4.29 2.54 1.90 0.50 V LOW V LOW2.600 V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH 25.16 13.99 8.40 4.59 2.72 V HIGH 0.53 V LOW V LOW2.700 V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH 26.96 15.00 9.01 4.92 2.91 V HIGH 0.55 V LOW V LOW2.800 V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH 16.01 9.61 5.25 3.10 V HIGH 0.57 V LOW V LOW2.900 V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH 17.08 10.25 5.60 3.31 V HIGH 0.60 V LOW V LOW3.000 V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH 18.15 10.88 5.94 3.51 V HIGH 0.62 V LOW V LOW3.200 V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH 20.41 12.23 6.67 3.94 V HIGH 0.70 V LOW V LOW3.400 V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH 22.79 13.65 7.44 4.39 V HIGH 0.79 V LOW V LOW3.600 V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH 15.15 8.25 4.86 V HIGH 0.87 V LOW V LOW3.800 V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH 16.71 9.10 5.36 V HIGH 0.96 V LOW V LOW4.000 V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH 18.35 9.98 5.88 V HIGH 1.04 V LOW V LOW4.200 V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH 20.06 10.91 6.42 V HIGH 1.14 V LOW V LOW4.400 V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH 11.87 6.98 V HIGH 1.24 V LOW V LOW4.600 V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH 12.86 7.57 V HIGH 1.35 V LOW V LOW4.800 V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH 13.90 8.17 V HIGH 1.45 V LOW V LOW5.000 V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH 14.97 8.80 V HIGH 1.55 0.37 0.445.500 V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH 17.82 10.46 V HIGH 1.85 0.45 0.536.000 V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH 12.25 V HIGH 2.14 0.52 0.616.500 V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH 14.17 V HIGH 2.49 0.60 0.717.000 V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH 2.83 0.68 0.807.500 V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH 3.21 0.77 0.918.000 V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH 3.59 0.86 1.019.000 V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH 4.44 1.06 1.25

10.000 V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH 5.37 1.28 1.5111.000 V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH V HIGH 6.39 1.52 1.79


73

Friction Factors for Polypark HDPE pipes (Iranian Standards) Head loss chart for HDP Pipe(ISI Standard)1.8 2.3 2.8 3.6 2.4 4.5 3 5.6 3.7 7.1 4.7 3 6.7 3.4 5.3ID (mm) 12.40 15.40 19.40 24.80 27.20 31.00 34.00 38.80 42.60 48.80 53.60 57.00 76.60 103.20 99.40OD (mm) 16 20 25 32 32 40 40 50 50 63 63 63 90 110 110Pressure 10kg/cm2 10kg/cm2 10kg/cm2 10kg/cm2 6kg/cm2 10kg/cm2 6kg/cm2 10kg/cm2 6kg/cm2 10kg/cm2 6kg/cm2 4kg/cm2 6kg/cm2 2.5kg/cm2 4kg/cm2

Flow (l/s) 16PN10 20PN10 25PN10 32PN10 32PN6 40PN10 40PN6 50PN10 50PN6 63PN10 63PN6 63PN4 90PN6 110PN2.5 110PN40.050 2.37 0.82 0.27 0.08 0.05 0.03 0.02 0.01 0.01 0.00 0.00 0.00 0.00 0.00 0.000.100 8.55 2.98 0.97 0.29 0.19 0.10 0.06 0.03 0.02 0.01 0.01 0.01 0.00 0.00 0.000.110 10.20 3.55 1.15 0.35 0.22 0.12 0.08 0.04 0.03 0.01 0.01 0.01 0.00 0.00 0.000.120 11.99 4.17 1.36 0.41 0.26 0.14 0.09 0.05 0.03 0.02 0.01 0.01 0.00 0.00 0.000.130 13.90 4.84 1.57 0.48 0.30 0.16 0.10 0.05 0.03 0.02 0.01 0.01 0.00 0.00 0.000.140 15.95 5.55 1.80 0.55 0.35 0.18 0.12 0.06 0.04 0.02 0.01 0.01 0.00 0.00 0.000.150 18.12 6.31 2.05 0.62 0.40 0.21 0.13 0.07 0.04 0.02 0.01 0.01 0.00 0.00 0.000.160 20.42 7.11 2.31 0.70 0.45 0.24 0.15 0.08 0.05 0.03 0.02 0.01 0.00 0.00 0.000.170 22.85 7.95 2.58 0.78 0.50 0.26 0.17 0.09 0.06 0.03 0.02 0.01 0.00 0.00 0.000.180 25.40 8.84 2.87 0.87 0.55 0.29 0.19 0.10 0.06 0.03 0.02 0.02 0.00 0.00 0.000.190 28.08 9.77 3.17 0.96 0.61 0.32 0.21 0.11 0.07 0.04 0.02 0.02 0.00 0.00 0.000.200 30.87 10.75 3.49 1.06 0.67 0.36 0.23 0.12 0.08 0.04 0.02 0.02 0.00 0.00 0.000.210 33.79 11.76 3.82 1.16 0.74 0.39 0.25 0.13 0.08 0.04 0.03 0.02 0.00 0.00 0.000.220 36.83 12.82 4.16 1.26 0.80 0.42 0.27 0.14 0.09 0.05 0.03 0.02 0.01 0.00 0.000.225 38.40 13.37 4.34 1.31 0.84 0.44 0.28 0.15 0.09 0.05 0.03 0.02 0.01 0.00 0.000.230 39.99 13.92 4.52 1.37 0.87 0.46 0.29 0.15 0.10 0.05 0.03 0.02 0.01 0.00 0.000.240 43.27 15.06 4.89 1.48 0.94 0.50 0.32 0.17 0.11 0.05 0.03 0.03 0.01 0.00 0.000.250 46.67 16.25 5.28 1.60 1.02 0.54 0.34 0.18 0.11 0.06 0.04 0.03 0.01 0.00 0.000.260 50.19 17.47 5.67 1.72 1.09 0.58 0.37 0.19 0.12 0.06 0.04 0.03 0.01 0.00 0.000.280 57.57 20.04 6.51 1.97 1.26 0.66 0.42 0.22 0.14 0.07 0.05 0.03 0.01 0.00 0.000.300 65.42 22.77 7.40 2.24 1.43 0.75 0.48 0.25 0.16 0.08 0.05 0.04 0.01 0.00 0.000.320 73.72 25.66 8.33 2.52 1.61 0.85 0.54 0.28 0.18 0.09 0.06 0.04 0.01 0.00 0.000.340 82.48 28.71 9.32 2.82 1.80 0.95 0.61 0.32 0.20 0.10 0.07 0.05 0.01 0.00 0.000.360 91.69 31.92 10.37 3.13 2.00 1.06 0.67 0.35 0.22 0.12 0.07 0.05 0.01 0.00 0.000.380 NA 35.28 11.46 3.46 2.21 1.17 0.75 0.39 0.25 0.13 0.08 0.06 0.01 0.00 0.000.400 NA 38.79 12.60 3.81 2.43 1.29 0.82 0.43 0.27 0.14 0.09 0.07 0.02 0.00 0.000.420 NA 42.46 13.79 4.17 2.66 1.41 0.90 0.47 0.30 0.15 0.10 0.07 0.02 0.00 0.000.440 NA 46.28 15.03 4.55 2.90 1.53 0.98 0.51 0.33 0.17 0.11 0.08 0.02 0.00 0.010.460 NA 50.25 16.32 4.94 3.15 1.66 1.06 0.56 0.35 0.18 0.12 0.09 0.02 0.00 0.010.480 NA 54.37 17.66 5.34 3.41 1.80 1.15 0.60 0.38 0.20 0.13 0.09 0.02 0.01 0.010.500 NA 58.64 19.05 5.76 3.67 1.94 1.24 0.65 0.41 0.21 0.13 0.10 0.02 0.01 0.010.520 NA 63.06 20.48 6.19 3.95 2.09 1.33 0.70 0.44 0.23 0.15 0.11 0.03 0.01 0.010.540 NA 67.63 21.96 6.64 4.24 2.24 1.43 0.75 0.48 0.25 0.16 0.12 0.03 0.01 0.010.550 NA 69.96 22.72 6.87 4.38 2.32 1.48 0.78 0.49 0.25 0.16 0.12 0.03 0.01 0.010.560 NA 72.34 23.49 7.10 4.53 2.40 1.53 0.80 0.51 0.26 0.17 0.12 0.03 0.01 0.010.580 NA 77.19 25.07 7.58 4.83 2.56 1.63 0.86 0.54 0.28 0.18 0.13 0.03 0.01 0.010.600 NA 82.20 26.70 8.07 5.15 2.72 1.74 0.91 0.58 0.30 0.19 0.14 0.03 0.01 0.010.620 NA 87.34 28.37 8.58 5.47 2.89 1.85 0.97 0.62 0.32 0.20 0.15 0.04 0.01 0.010.640 NA 92.63 30.08 9.10 5.80 3.07 1.96 1.03 0.65 0.34 0.21 0.16 0.04 0.01 0.010.650 NA 95.33 30.96 9.36 5.97 3.16 2.01 1.06 0.67 0.35 0.22 0.16 0.04 0.01 0.010.660 NA 98.06 31.85 9.63 6.14 3.25 2.07 1.09 0.69 0.36 0.23 0.17 0.04 0.01 0.010.680 NA NA 33.66 10.18 6.49 3.43 2.19 1.15 0.73 0.38 0.24 0.18 0.04 0.01 0.010.700 NA NA 35.52 10.74 6.85 3.62 2.31 1.21 0.77 0.40 0.25 0.19 0.04 0.01 0.010.720 NA NA 37.42 11.31 7.22 3.82 2.43 1.28 0.81 0.42 0.27 0.20 0.05 0.01 0.010.740 NA NA 39.37 11.90 7.59 4.02 2.56 1.35 0.85 0.44 0.28 0.21 0.05 0.01 0.010.750 NA NA 40.36 12.20 7.78 4.12 2.62 1.38 0.88 0.45 0.29 0.21 0.05 0.01 0.010.760 NA NA 41.36 12.51 7.98 4.22 2.69 1.41 0.90 0.46 0.29 0.22 0.05 0.01 0.010.780 NA NA 43.40 13.12 8.37 4.43 2.82 1.48 0.94 0.49 0.31 0.23 0.05 0.01 0.020.800 NA NA 45.48 13.75 8.77 4.64 2.96 1.55 0.99 0.51 0.32 0.24 0.06 0.01 0.020.850 NA NA 50.88 15.39 9.81 5.19 3.31 1.74 1.10 0.57 0.36 0.27 0.06 0.01 0.020.900 NA NA 56.56 17.10 10.91 5.77 3.68 1.93 1.23 0.63 0.40 0.30 0.07 0.02 0.020.950 NA NA 62.52 18.91 12.06 6.38 4.07 2.14 1.36 0.70 0.44 0.33 0.08 0.02 0.021.000 NA NA 68.75 20.79 13.26 7.01 4.47 2.35 1.49 0.77 0.49 0.36 0.09 0.02 0.021.050 NA NA 75.25 22.76 14.51 7.68 4.89 2.57 1.63 0.84 0.53 0.40 0.09 0.02 0.031.100 NA NA 82.02 24.80 15.82 8.37 5.33 2.80 1.78 0.92 0.58 0.43 0.10 0.02 0.031.150 NA NA 89.06 26.93 17.17 9.08 5.79 3.04 1.93 1.00 0.63 0.47 0.11 0.03 0.031.200 NA NA 96.36 29.14 18.58 9.83 6.27 3.29 2.09 1.08 0.68 0.51 0.12 0.03 0.031.250 NA NA NA 31.43 20.04 10.60 6.76 3.55 2.25 1.16 0.74 0.55 0.13 0.03 0.041.300 NA NA NA 33.80 21.55 11.40 7.27 3.82 2.42 1.25 0.79 0.59 0.14 0.03 0.041.350 NA NA NA 36.24 23.11 12.22 7.80 4.10 2.60 1.34 0.85 0.63 0.15 0.03 0.041.400 NA NA NA 38.77 24.72 13.08 8.34 4.38 2.78 1.43 0.91 0.67 0.16 0.04 0.041.450 NA NA NA 41.37 26.38 13.95 8.90 4.68 2.97 1.53 0.97 0.72 0.17 0.04 0.051.500 NA NA NA 44.05 28.09 14.86 9.47 4.98 3.16 1.63 1.03 0.77 0.18 0.04 0.051.550 NA NA NA 46.81 29.85 15.79 10.07 5.29 3.36 1.73 1.10 0.81 0.19 0.05 0.051.600 NA NA NA 49.64 31.66 16.74 10.68 5.61 3.56 1.84 1.16 0.86 0.20 0.05 0.061.650 NA NA NA 52.55 33.51 17.73 11.30 5.94 3.77 1.94 1.23 0.91 0.22 0.05 0.061.700 NA NA NA 55.54 35.42 18.73 11.95 6.28 3.98 2.06 1.30 0.96 0.23 0.05 0.061.750 NA NA NA 58.60 37.37 19.77 12.61 6.63 4.20 2.17 1.37 1.02 0.24 0.06 0.071.800 NA NA NA 61.74 39.37 20.83 13.28 6.98 4.43 2.28 1.45 1.07 0.25 0.06 0.071.850 NA NA NA 64.95 41.42 21.91 13.97 7.34 4.66 2.40 1.52 1.13 0.27 0.06 0.081.900 NA NA NA 68.24 43.52 23.02 14.68 7.72 4.89 2.53 1.60 1.19 0.28 0.07 0.081.950 NA NA NA 71.61 45.66 24.15 15.40 8.10 5.14 2.65 1.68 1.24 0.29 0.07 0.082.000 NA NA NA 75.04 47.85 25.31 16.14 8.48 5.38 2.78 1.76 1.30 0.31 0.07 0.092.100 NA NA NA 82.14 52.38 27.71 17.67 9.29 5.89 3.04 1.92 1.43 0.34 0.08 0.102.200 NA NA NA 89.53 57.09 30.20 19.26 10.12 6.42 3.31 2.10 1.55 0.37 0.09 0.102.300 NA NA NA 97.21 61.99 32.79 20.91 10.99 6.97 3.60 2.28 1.69 0.40 0.09 0.112.400 NA NA NA NA 67.07 35.48 22.62 11.89 7.54 3.89 2.46 1.83 0.43 0.10 0.122.500 NA NA NA NA 72.34 38.26 24.40 12.83 8.14 4.20 2.66 1.97 0.47 0.11 0.132.600 NA NA NA NA 77.79 41.15 26.24 13.79 8.75 4.51 2.86 2.12 0.50 0.12 0.142.700 NA NA NA NA 83.42 44.12 28.14 14.79 9.38 4.84 3.07 2.27 0.54 0.13 0.152.800 NA NA NA NA 89.23 47.20 30.10 15.82 10.04 5.18 3.28 2.43 0.58 0.13 0.162.900 NA NA NA NA 95.23 50.37 32.12 16.88 10.71 5.53 3.50 2.59 0.61 0.14 0.173.000 NA NA NA NA NA 53.63 34.20 17.98 11.40 5.88 3.73 2.76 0.65 0.15 0.183.200 NA NA NA NA NA 60.44 38.54 20.26 12.85 6.63 4.20 3.11 0.74 0.17 0.213.400 NA NA NA NA NA 67.62 43.12 22.67 14.38 7.42 4.70 3.48 0.83 0.19 0.233.600 NA NA NA NA NA 75.17 47.94 25.20 15.98 8.25 5.22 3.87 0.92 0.21 0.263.800 NA NA NA NA NA 83.09 52.98 27.85 17.67 9.12 5.77 4.28 1.01 0.24 0.294.000 NA NA NA NA NA 91.37 58.26 30.62 19.43 10.02 6.35 4.70 1.12 0.26 0.314.200 NA NA NA NA NA NA 63.77 33.52 21.27 10.97 6.95 5.15 1.22 0.29 0.344.400 NA NA NA NA NA NA 69.51 36.54 23.18 11.96 7.57 5.61 1.33 0.31 0.374.600 NA NA NA NA NA NA 75.48 39.67 25.17 12.99 8.22 6.09 1.44 0.34 0.414.800 NA NA NA NA NA NA 81.66 42.92 27.23 14.05 8.90 6.59 1.56 0.37 0.445.000 NA NA NA NA NA NA 88.08 46.30 29.37 15.15 9.60 7.11 1.69 0.39 0.475.500 NA NA NA NA NA NA NA 55.23 35.04 18.08 11.45 8.48 2.01 0.47 0.576.000 NA NA NA NA NA NA NA 64.89 41.17 21.24 13.45 9.97 2.36 0.55 0.666.500 NA NA NA NA NA NA NA 75.26 47.74 24.63 15.60 11.56 2.74 0.64 0.777.000 NA NA NA NA NA NA NA 86.33 54.77 28.26 17.89 13.26 3.14 0.74 0.887.500 NA NA NA NA NA NA NA 98.09 62.23 32.11 20.33 15.07 3.57 0.84 1.008.000 NA NA NA NA NA NA NA NA 70.13 36.18 22.91 16.98 4.03 0.94 1.139.000 NA NA NA NA NA NA NA NA 87.22 45.00 28.50 21.12 5.01 1.17 1.41

10.000 NA NA NA NA NA NA NA NA NA 54.70 34.64 25.67 6.09 1.43 1.7111.000 NA NA NA NA NA NA NA NA NA 65.26 41.32 30.63 7.26 1.70 2.04


74

WHO's Guidelines for Drinking-water Quality, set up in Geneva, 1993, are the international reference point for standard setting and drinking-water safety. Element/ substance

Symbol/ formula

Normally found in fresh water/surface water/ground water

Health based guideline by the WHO

Aluminium Al 0,2 mg/l Ammonia NH4 < 0,2 mg/l (up to 0,3 mg/l in

anaerobic waters) No guideline

Antimony Sb < 4 μg/l 0.005 mg/l Arsenic As 0,01 mg/l Asbestos No guideline Barium Ba 0,3 mg/l Berillium Be < 1 μg/l No guideline Boron B < 1 mg/l 0,3 mg/l Cadmium Cd < 1 μg/l 0,003 mg/l Chloride Cl 250 mg/l Chromium Cr+3, Cr+6 < 2 μg/l 0,05 mg/l Colour Not mentioned Copper Cu 2 mg/l Cyanide CN- 0,07 mg/l Dissolved oxygen O2 No guideline Fluoride F < 1,5 mg/l (up to 10) 1,5 mg/l Hardness mg/l CaCO3 No guideline Hydrogen sulfide H2S No guideline Iron Fe 0,5 - 50 mg/l No guideline Lead Pb 0,01 mg/l Manganese Mn 0,5 mg/l Mercury Hg < 0,5 μg/l 0,001 mg/l Molybdenum Mb < 0,01 mg/l 0,07 mg/l Nickel Ni < 0,02 mg/l 0,02 mg/l Nitrate and nitrite NO3, NO2 50 mg/l total nitrogen Turbidity Not mentioned pH No guideline Selenium Se < < 0,01 mg/l 0,01 mg/l Silver Ag 5 – 50 μg/l No guideline Sodium Na < 20 mg/l 200 mg/l Sulfate SO4 500 mg/l Inorganic tin Sn No guideline TDS No guideline Uranium U 1,4 mg/l Zinc Zn 3 mg/l


75

Disinfectants and disinfectant by-products

Group Substance Formula Health based guideline by the WHO

Disinfectants Chloramines NHnCl(3-n), where n = 0,1 or 2

3 mg/l

Chlorine Cl2 5 mg/l Chlorine dioxide ClO2 No guideline Iodine I2 No guideline

Disinfectant by-products

Bromate Br O3- 25 μg/l

Chlorate Cl O3- No guideline

Chlorite Cl O2- 200 μg/l

Chlorophenols 2-Chlorophenol (2-CP) C6 H5 Cl O No guideline 2,4-Dichlorophenol (2,4-DCP) C6 H4 Cl2 O No guideline 2,4,6-Trichlorophenol (2,4,6-TCP) C6 H3 Cl3 O 200 μg/l

Formaldehyde HCHO 900 μg/l MX (3-Chloro-4-dichloromethyl-5-hydroxy-2(5H)-furanone)

C5 H3 Cl3 O3 No guideline

Trihalomethanes Bromoform C H Br3 100 μg/l Dibromochloromethane CH Br2 Cl 100 μg/l Bromodichloromethane CH Br Cl2 60 μg/l Chloroform CH Cl3 200 μg/l

Chlorinated acetic acids

Monochloroacetic acid C2 H3 Cl O2 No guideline Dichloroacetic acid C2 H2 Cl2 O2 50 μg/l Trichloroacetic acid C2 H Cl3 O2 100 μg/l

Chloral hydrate (trichloroacetaldehyde) C Cl3 CH(OH)2 10 μg/l Chloroacetones C3 H5 O Cl No guideline Halogenated acetonitriles

Dichloroacetonitrile C2 H Cl2 N 90 μg/l Dibromoacetonitrile C2 H Br2 N 100 μg/l Bromochloroacetonitrile CH Cl2 CN No guideline Trichloroacetonitrile C2 Cl3 N 1 μg/l

Cyanogen chloride Cl CN 70 μg/l Chloropicrin C Cl3 NO2 No guideline


76

Project:___________________ Families/member: Page No._________________District/Province: ___________________________________Yield: ___________________ Instrument:______________Tap Stands: Date :_____________________ Observed By:_____________Others demands: Recorded By:_____________

StationSloped Distance

(m)Vertical Angle

(d)Vertical Distance

(m) S SDReduced Level

(m) Remarks

ABNEY LEVEL OBSERVATION BOOK (GWSS)


77

River

Date Salt Constant k µS/(mg/ml)

Time Water temp o C

Weather Base level µS

Salt Used (M)

5 10 15 20 25 30 35 40 45 50 55 60 Sum

Total

Time(sec)

Water Conductivity

in µS

Discharge Measurement Using Conductivity Meter


78

LEVEL OBSERVATION BOOKProject:___________________ Page No._________________Date :_____________________ Instrument:______________Time:______________________ Observed By:_____________Weather:___________________ Recorded By:_____________Staff Distance/ Staff Reading Height Rise Fall Reduced RemarksStn Chainage Back Inter Fore of Inst Level


79

STADIA OBSERVATION BOOKProject:________________ Page:___________Time:___________________ Date:_________________________Weather:________________ Instrument:___________________Instrument Height:______ Observed By:__________________Location:______________________________Recorded By:__________________Inst Height Face Horiz. Vert. Stadia Readings RemarksStn of Inst Angle Angle Top Middle Bottom


80

Project Name : Designed by : Date:District name : Checked by : Date:Source Name : Approved by : Date:

Static HGL Design Pipe lenght head Desired Desired frictional Pipe Frictional head loss HGL Residual No of fittings

station 1 station 2 Station 1 Station 2 pressure head station 1 flow ground design availableresidual

head head loss

head loss

factorclass &

dia. factor partial station 2head

station 2(name) (name) (m) (m) (m) (m) ( l.p.s.) (m) (m) (m) ( m ) ( m ) ( % ) ( % ) ( m ) (m) (m)

A B C D E F G H I J K L M N O P Q R

[Hx 1.1] [F - D] [J - K][L/I x 100%]

[(O x I) /100] [F - P] [Q - D]

ElevationReach

P I P E DESIGN F O R M A T


81

REFERENCES

1. Amar Nekhu & Edward A. Hillmann, Rural Gravity Flow Water System (Design Techniques and Standard Structures), UNICEF & Govt. of Nepal, Kathmandu, Nepal (1996).

2. Gravity Water Supply Design Notes and Formats, CARE International in Nepal, Kathmandu, Nepal.

3. Gravity Water Supply Design Notes and Formats, Rural Area Development Program (RADP/CIDA), Government of Nepal, Kathmandu, Nepal.

4. Gravity Water Supply Design Notes and Formats, United Mission to Nepal, Kathmandu, Nepal.

5. Lane Brown, Understanding Gravity-Flow Pipelines, Water Flow, Air Locks and Siphons, Ministry of Agriculture and Lands, British Columbia, Canada, 2006.

6. National Solidarity Program (NSP) Afghanistan, Technical Manuals on WatSan (2007).

7. Oasis Design, Slow Sand Filtration at www.oasisdesign.net, 2006.

8. P.N. Khanna (1996), Indian Practical Civil Engineer's Handbook, 15th Edition, Engineer's Publishers, Post Box 725, New Delhi - 110001.

9. Provision of Drinking Water and System of Water Supply Scheme, National Solidarity Programme, Kabul, Afghanistan (2007).

10. Pushpa Chitrakar (2007), Discharge Measurement and Engineering Surveying Tools, UNHABITAT, Afghanistan, ISBN 978-969-9212-00-0.

11. Pushpa Chitrakar, Design of Sixteen Gravity Water Flow Systems, Jhimruk Hydro-electric and Rural Electrification Project (JHEREP), Pyuthan, Nepal (1991).

12. Pushpa Chitrakar, Gravity Water Supply Pipe Network Design Spreadsheet, Rural Area Development Program (RADP/CIDA), Government of Nepal, Kathmandu, Nepal.

13. Pushpa Chitrakar, Micro-hydropower Design Aids, Mini-Grid Support Programme, Alternative Energy Promotion Centre, Kathmandu, Nepal (2003).

14. Pushpa Chitrakar, Mini-hydropower Design Aids, Small Hydropower Promotion Project/German Technical Cooperation (SHPP/GTZ), Kathmandu, Nepal (2006). Download: www.entec.com.np.

15. Pushpa Chitrakar, Notes on Closed Traverse Surveying and Data Reduction (1991), Butwal Power Company Limited, Nepal, 1991.

16. S K Garg, Water Supply Engineering, Khanna Publishers, Delhi, India (2007).

http://www.oasisdesign.net

http://www.entec.com.np


82

17. S. C. Rangwala, Fundamentals of Water Supply and Sanitary Engineering, Charotar Publishing House, Mumbai, India (2001)

18. Standardization for Rural Water Supply System, Ministry of Housing and Physical Planning, Department of Water Supply and Sewerage, Western Regional Directorate, Nepal.

19. Thomas D. Jordan, Jr., Handbook of Gravity Water System, UNICEF, Kathmandu, Nepal (1980).

20. Water Supply Technical Manual, Rural Assistance Program, CARE International in Afghanistan, Kabul, Afghanistan (2006).


83

TYPICAL DRAWINGS

1. General Layout: Plan

2. Headworks General Layout: Plan

3. Weir: Plan and Sections

4. Sedimentation Tank: Plans and Sections

5. Slow Sand Filter Tank: Plans and Sections

6. 50m3 Reservoir Tank: Plan, Section and Details

7. 25m3 Reservoir Tank: Plan, Sections

8. 25m3 Reservoir Tank: Reinforcement Details

9. Pipe Networks System: Pipe Design

10. Pipe Networks System: Profile

11. Miscellaneous Details: Manhole, Tap-stand and Pipe Laying

12. Break Pressure Tank: With and Without Float Valves

13. Spring Intake: Plan and Section

14. Stream Intake with in-built Filter: Plan and Sections

1mmin

d2

h

1mmin

. d2

4.10

1.00

0.75

0.20

0.30

Varies

0.20

0.30

Varies

1.00

500min

0.20W=

0.30

0.30

4.20

3.00

0.601.950.30

0.750.60

0.30

2.80

0.30

2.80

0.90

1.00

0.30

2.80

0.58

2.80

0.50

3.00

0.401.280.10

0.300.403.50

0.40 0.30

4.90

0.81

0.15

0.151.801.150.400.75

0.952.150.20

0.20

0.35

1.50

3.00

9.35

1.500.30

2.700.30

2.600.30

2.500.400.45

3.05

0.10

0.66

0.30

12.55

4.50

1.00

1.700.10 0.10

0.100.20

0.820.68

-

0.30

0.40

0.55

0.70

0.300.55

50,PN6,330m

50,PN6,101.4m174m

300m

16,PN10, 11m

16,PN10, 11m

20,PN10, 11m

20,PN10, 11m

2666.7752666.775IntakeatDokhani 0.924

Elevation(m)

63PN6

2666.0182658.63Combination 0.924180.00

2630.002630.00ReservoirtankatJn00 1.5752020.00

2618.5882586.19Jn01 1.350330.00

2613.6132589.85Jn02 1.125191.40

2609.0842586.76Jn03 0.900244.202607.8962584.34Jn04 0.67596.80

2605.0682585.67Jn05 0.450392.70

2601.8732582.70Jn06 0.225313.50

2600.0482582.70Combination 0.225218.00

2567.1852551.84Tap07 757.00

50PN6

40PN6

32PN6

25PN10

50PN6

50PN6

50PN6

50PN650PN6

0.400.70

0.85

0.050.50

0.200.20

0.80min

1.45

0.150.10

0.980.100.12

0.15 1.000.15

1.30

1.45

0.150.10

1.10

1.100.10

0.15 1.000.15

1.30

0.30

1.45

0.150.10

1.100.10

0.15 1.000.15

1.30

0.35L0.35

0.40

0.20

0.500.350.05

0.20

0.150.800.100.40

Varies

A

0.500.50 2.000.05

12.00

0.60

6.00 6.00

0.501.000.50

1.00

1.000.60

1.45

2.00

United Nations Human Settlements Programme (UNHABITAT), Afghanistan

The United Nations Human Settlements Programme, UN-HABITAT, established in 1978, is the lead agency within the UN system for coordinating activities in the field of human settlement development.

The headquarter of UN-HABITAT is located in Nairobi, Kenya and it has its three regional offices as:

a. Regional Office for Asia and Pacific (ROAP) in Fukuoka, Japan

b. Regional Office for Latin and the Caribbean (ROLAC) in Rio de Janeiro, Brazil

c. Regional Office for Africa and the Arab States (ROAAS) in Nairobi, Kenya.

UN-HABITAT, Afghanistan operates under the ROAP. It has more than 15 years of history of operation in Afghanistan. Through conflicts and wars, it has been serving the people of Afghanistan without any interruption. Through its programmes and projects, it has been serving and assisting more than seven million rural and urban populations. It has implemented reconstruction, infrastructure development, education and community empowerment projects and programmes with a total cost of about US$ 60 million. At present, UN-HABITAT, Afghanistan is staffed with about one thousand national staff and six international staff in 48 districts of nine provinces and the main office in Kabul.

Within the national development frameworks and national priority programmes, UN-HABITAT is assisting the Islamic Republic of Afghanistan in translating its development efforts into tangible outputs, improving the quality of livelihood of Afghan citizens. Its current activities include:

1. Strengthening of Policy Framework: UN-HABITAT provides inputs to the formulation of national development policies, acts and regulations.

2. Project implementation: UN-HABITAT is engaged in implementing rural and urban community-based infrastructure as well as human security sub-projects. To date, it has implemented more than 6000 such sub-projects in Afghanistan.

3. Capacity building of stakeholders: UN-HABITAT is involved in developing indigenous capacity of Afghan human resources towards sustainability. On-the-job training while implementing sub-projects, seminars, workshops and forums for professionals and stakeholders of development perspective are some of the methods used during capacity building.

4. Facilitating Grants: UN-HABITAT is successful in attracting major donors on implementing their development grants efficiently and effectively. National Solidarity Program (NSP), Literacy and Community Empowerment Programme (LCEP), Inter Communal Rural Development Project (IRDP), Reintegration of Returnees and internally displaced people in Informal Settlements in Kabul (EC5), Human Security Trust Fund (HSTF) and Youth Empowerment Programme (YEP) are the major programmes and projects being facilitated by UN-HABITAT.

Contact Address:

UN-HABITAT, Afghanistan

House # 235, Street # 8,

Taimani, Kabul, Afghanistan

e-mail: [email protected]


gravity water supply system tools manual

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