CONTENTSPRIVATE

1. SCOPE

2. GENERAL

2.1 Applicable Codes and Standards

2.2 Design Philosophy

2.3 Piping Sizes

2.4 Joints

2.5 Valve Location

2.6 Valve Size

2.7 Pipe Support

2.8 Criteria for Thermal Expansion and Uneven Settlement

2.9 Force and Moment on Mechanical Equipment

2.10 Relief System Piping

2.11 Piping for Instruments

2.12 Drain and Vent

2.13 Utility Station

2.14 Underground Piping

2.15 Trench Piping

2.16 Sample Connection

2.17 Utility Piping

2.18 Minimum Clearance

2.19 Pipe through Floors

3. PIPING AROUND EQUIPMENT

3.1 Tower and Drum Piping

3.2 Piping for Rotating Machines

3.3 Heat Exchanger Piping

3.4 Furnace Piping

3.5 Tank Farm Piping

3.6 Pipe way Piping

3.7 Steam Trace Piping

3.8 Jacketed Piping

4. PIPING DRAWING

4.1 Process and Utility Unit

4.2 Utility Unit Off-Site

4.3 Scale

4.4 Letters

4.5 Size of Drawings

APPENDIX 1

1. SCOPE 1.1This Specification covers the General Requirements for piping design.

1.2The intent of this standard is not to supersede ANSI piping code, but only to supplement, amend or limit it as required.

2. GENERAL 2.1Applicable Codes and Standards

(Latest Editions unless otherwise specified)

(1)Design code

ASME / ANSI B 31.3 : - 87 (88)Chemical Plant and Petroleum Refinery Piping

ANSI / ASME B 31.1 : - 1986Power piping (For piping as part of steam generation (system))

ASME / ANSI B 31.4 : - 1986Liquid transportation systems for hydrocarbon, liquid petroleum gas, anhydrous ammonia, and alcohol

(2)Material specifications : ASTM or JIS equivalent.

Individual materials shall be as shows in Piping Material Specification. When JIS is applied, the equivalent ASTM shall be specified in the documents.

(3)Dimensions

(a) Pipe : ANSI or API standards

(b) Fitting : ANSI or API standard

(c) Flange : ANSI and API standard

(d) Valve : ANSI, API and manufacturer's standard

2.2Design Philosophy

The plant, equipment layout and relevant piping arrangement shall be performed in consideration of the following.

(1)Construction and maintenance requirements

Sufficient space shall be provided for the efficient/effective use of mobile equipment for the construction, maintenance and revamping work of the plant.

(2)Operational requirements

Easy access for daily operation/maintenance of various instruments, valves etc. shall be assured to enable proper and safe plant operation.

(3)Safety requirements

The roads, access-ways and fire fighting equipment shall be arranged in consideration of space requirement for safety, and advantage to taking prompt action in case of emergency. High risk facilities or equipment handling toxic or hazardous fluid, shall be segregated to minimize involvement of adjacent facilities in an emergency, and prevent further equipment failures.

(4)Economical requirements

Equipment and piping shall be laid out/arranged to minimize the total length of pipes, especially large-size and low-alloy steel pipes. At the same time, the route of relevant electrical and instrument cables shall be laid out to minimize the total length of cable.

2.3Piping Sizes

(1)Nominal sizes in inches 1-1/4, 3-1/2 and 5 shall not be used for metallic piping.

(2)Minimum size of piping components shall be as follows :

Steel piping components: 1/2 " NPS

Steel tubing : 3/8 " NPS

(3)Where unusual sizes are required for connecting to equipment, piping is normally run in the next larger after connection has been made unless otherwise restricted by special requirement.

(4)Header piping sizes shall maintain min.1" except auxil piping, such as steam tracers to avoid excess deflection.

2.4Joints

(1)Flanges of piping shall be a minimum in number, and provided only for ease of maintenance and inspection, or where construction or process conditions required.

(2)Socket welded joints shall be limited to size 2" NPS or less.

(3)Threaded joints may be used for water and air service in size 1-1/2" PS and less.

(4)Butt-welding joints are preferable. Welding and its preparation shall conform to ASME/ANSI B 16.25 Fig. 2 (9) or Fig. 3 (a).

(5)High frequency induction bend piping apply to carbon steel seamless pipe of 2" NPS through 12"NPS.

2.5Valve Operation

(1)In general, valves shall be located so that they can be operated at grade or from a platform.

(2)In case of horizontal stem valves (including hand wheel for gear operation), the height of valve center shall be kept within 1.8 m high from grade or platform.

Where possible, valves shall preferably be located 1.2 m above grade or platform.

Where the height of a valve stem is more than 1.8 m above grade or the operating floor, operating steps or chain operation shall be provided. However, chain operation shall not be used for valves 2" NPS and smaller.

(3)Operation of valves from a ladder shall be acceptable, where the valves mentioned below are located more than 1.8 m above grade or platform.

(a)Block valves of NPS 2" and smaller

(b)Block valves of pressure gauges and pressure instruments

(c)Tap valves at orifice flanges

(d)Valves for piping and equipment vents and drains

(4)In case of vertical stem valves, the maximum hand wheel height shall be 1.6 m above the operating floor, in general. Where the height exceeds the above mentioned valve, an operating step shall be provided.

(5)In case of valves located below platforms, if their hand wheels do not extend beyond the platform floors, extension stems shall be used.

(6)Sheet 24 of 24 of this specification shall be used as a quide.

2.6Valve Size

(1)Unless otherwise specified in P&ID, pump suction strainers and valves including pump discharge valves shall be sized as follows :

(a)Suction valve size and strainer size are same as line size where pumps nozzle size is same or one size smaller than the line.

(b)One size smaller than the suction line where pump nozzle size is two or three sizes smaller than the line.

(c)Where the pumps discharge line is larger than the pump discharge nozzle, its check valve, if required, and its shut-off valve shall be one size larger than the discharge size of the pump.

(2)Valves at control valve manifolds shall be sized in accordance with the following table, unless otherwise shown on the Piping and Instrument Diagram : (All dimensions are inches).

PRIVATE Line SizeCONTROL

Valve SizeBlock Valve SizeBy-pass

Valve Size

3/4"3/4"3/4"3/4"

1"3/4", 1"1"1"

1-1/2"3/4"

1", 1-1/2"1-1/2"

1-1/2"1"

1-1/2"

2"3/4"

1"

1-1/2", 2"2"

2"

2"1"

1-1/2"

2"

3"3/4"

1"

1-1/2"

2", 3"2"

2"

2"

3"1"

1-1/2"

2"

3"

4"3/4"

1"

1-1/2"

2"

3", 4"2"

2"

2"

3"

4"1"

1-1/2"

2"

3"

4"

6"2"

3"

4", 6"3"

4"

6"3"

4"

6"

8"3"

4"

6", 8"4"

6"

8"4"

6"

8"

10"4"

6"

8", 10"6"

8"

10"6"

8"

10"

12"6"

8"

10"

8"

10"

12"

8"

10"

12"

When reducers are used the maximum reduction shall not be greater than two nominal line sizes per reducer.

2.7Pipe Support

(1)The loads which shall work on pipe supports, shall be calculated based on the following criteria :

(a)Dead weight of pipe

(b)Gas/Steam/Air: 0

Water

: 1.0 (specific gravity)

Other Fluids : Each fluid it self shall be used

(c)Valves, safety valves and control valves subject to concentrated loads

(d)Weight of insulation specific gravity

(2)The support spans of horizontal piping and of vertical piping shall be as shown below :

1/2" NPS

Maximum

3.5 m

3/4" NPS

Maximum

4.0 m

1" NPS

Maximum

4.5 m

1-1/2" NPS

Maximum

5.5 m

2" NPS

Maximum

6.0 m

3" NPS

Maximum

7.0 m

4" NPS

Maximum

8.0 m

6" NPS

Maximum

9.0 m

8" NPS

Maximum

10.0 m

10" NPS

Maximum

11.0 m

12" NPS and overMaximum

12.0 m

(3)Supports to be attached in inlet or outlet piping of pumps, compressors and steam turbines shall be "adjustable" type. Dummy support shall be avoided.

(4)Supports receiving vertical loads for the high temperature piping shall be "spring" type, depending on the thermal calculation.

(5)Supports for piping which is subject to vibrations shall be designed to diminish resonance.

(6)Operating pipe shall not be used as support. However, small bore piping is acceptable supporting from adjacent larger pipe to prevent excess deflection.

2.8Criteria for Thermal Expansion and Uneven Settlement(1)Thermal stress calculations shall be conducted in accordance with ANSI B31.3

(2)Steam condensate lines shall be provided with expansion sleeves where necessary. And pipe expansion loop can be used also where no limitation from process requirements.

(3)Expansion loops shall principally be used to piping systems to prevent thermal expansion or contraction.

2.9Force and Moment on Mechanical Equipment

All piping systems shall assure by means of analyzing as per most severe condition to against excess expansion or contraction. When piping systems is analyzed, actual operating temperature of equipment and piping shall be used. Force and moment on mechanical equipment shall not exceed the following conditions.

(1)Vendor's recommendation values.

(2)Individual equipment specification (if specified).

(3)Applicable codes and standards and as modified by the equipment specifications.

2.10Relief System Piping 2.10.1General

The design and installation of pressure-relieving systems shall be in accordance with API RP 520 "Design and Installation of pressure Relieving System in Refinery".

2.10.2Open System

In Order to protect personnel from hazard and equipment from damage, the location of the atmospheric discharge of flammable and hazardous vapor shall be accurately decided in accordance with the following requirements.

(1)Where pressure relief valves discharge the vapor to atmosphere, the vent line shall terminate at least 3 m above equipment or any service platform located within a radius of 13 m from the valve. Such valves shall be located at the highest practical elevation on vertical vessels.

(2)Where pressure relief valves discharge steam to the atmosphere, the vent line shall terminate at least 3 m above any service platform located within approximately 7.5 m from the valve.

(3)9 mm diameter weep hole shall be provided for drainage at a low point of the discharge piping.

2.10.3Closed System

(1)The outlet line from the relief valve shall be self-draining into the flare header.

(2)The outlet piping from the relief valve shall be connected to the top part of the header at a 45 degree angle to the flow direction, but a 1-1/2" NPS or smaller piping may be connected at right angles to the flow direction.

2.11Piping for Instruments

2.11.1 General

(1)The instruments shall be so located that they will not be exposed to damage during operation, inspection or maintenance of equipment.

(2)All measuring elements shall be installed at locations where exact measurements can be taken, free from disturbances due to access for operation and maintenance. The positions of instruments shall be selected so that their readings are visible from ground level, platform, ladders or steps.

2.11.2 Pressure Instrument

(1)The piping for pressure instruments shall not be branched off from the bottom side of the line.

2.11.3 Flow Instrument

(1)Orifices shall be installed in horizontal pipes, as far as possible. When it is impossible to find sufficient straight length in a horizontal piping, orifices may be installed in a vertical piping with downward flow for liquid, gas and steam.

(2)The minimum straight length required for both upstream and downstream of the orifice.

2.11.4 Temperature Instrument

(1)The location of thermowells shall be arranged so as to maintain sufficient space for insertion of temperature instruments.

(2)Thermowells shall be located at least ten (10) times the pipe inside diameter downstream from the mixing point of two (2) different temperature streams.

2.11.5 Control Valve

(1)Control valves shall be located so as to facilitate maintenance and manual operation from the operating floor.

(2)Control valves shall normally be installed in horizontal piping with the valve stem vertically upward.

(3)Sufficient clearance shall be provided above the diaphragm and below the bottom of the body for easy maintenance.

(4)Control valve shall be located at the place to make easy the operator's manipulation and close to process equipment for reliability of operation.

If possible and does not affect to the reliability of operation, control valve preferably be located at the ground level.

(5)Connection of control valve is CL.300 rating minimum.

2.11.6 Instrument cable way

(1)Cable runs between onsite central control room and battery limit of the process units and/or in unpaved are shall be directly buried underground.

(2)Cable runs inside process units shall be buried underground in preformed concrete (concrete hollow block or solid concrete block) trench for main cables form outstation to field junction boxes.

(3)Cable runs forms field junction boxes to individual plant-mounted instrument shall be run overhead in galvanized perforated cable tray for branch cables on pipe rack.

2.12 Drain and Vent

(1)In piping systems, drains shall be provided at low points of all piping, and vents shall be provided at high points of piping as per P&ID requirements or the following requirements (If P&ID is not specified).

(a)Drain

(i)Alloy, stainless, class 900 rating and higher C.S piping except H2 service and class 600 rating and higher C.S piping for H2 service. - 3/4" NPS valve with blind flange.

(ii)Class 600 rating and lower C.S piping except H2 service and class 300 rating and lower C.S piping for H2 service. - 3/4" NPS valve with threaded plug (or valve with pipe nipple and cap for PWHT line).

(b)Vent

(i)Alloy, stainless, class 900 rating and higher C.S piping except H2 service and class 600 rating and higher C.S piping for H2 service. - 3/4" NPS valve with blind flange.

(ii)Class 600 rating and lower C.S piping except H2 service and class 300 rating and lower C.S piping for H2 service. - 3/4" NPS valve with threaded plug (or valve with pipe nipple and cap for PWHT line).

(iii)Required for hydrostatic testing purposes, alloy, stainless, class 900 rating and higher C.S piping except H2 service and class 600 rating and higher C.S piping for H2 service. - 3/4" NPS blank off.

(iv)Required for hydrostatic testing purposes, class 600 rating and lower C.S piping except H2 service and class 300 rating and lower C.S piping for H2 service. - 3/4" threaded plugged (to be seal welded after testing).

Note : 1.Where run pipe size is 1/2" NPS, the size of drain or vent valves shall be 1/2" NPS.

2.Applied valve type shall conform to P&ID and / or material specification requirements.

2.13Utility Station (Hose Station)

(1)Hose station shall be provided at 30 m intervals around the vessels and ground.

(2)Size :Water air nitrogen ... 3/4" NPS

Steam ................ 1" NPS

(3)Fluids :Water, air and steam (nitrogen, if necessary)

All items shall be terminated with hose connections.

(4)Hose connections shall be installed in the order of air, water and steam from left to right, facing to a utility station.

2.14Under-ground Piping

(1)Under-ground piping shall be laid at depths appropriate for the various loads.

(2)Under-ground piping shall have a covering soil layer of 300 mm minimum.

(3)Minimum cover for buried pipelines shall comply with table 434.6 (a) of ASME / ANSI B 31.4 - 1986.

(4)Corrosion protection shall be applied to all piping to be installed underground.

(5)Insulated piping shall be provided with corrosion protection coated sleeves.

(6)Corrosion protection shall comply with construction specification.

2.15Trench Piping

(1)Where it is required to install process piping underground inside the plot limits, e.g. in case of pump suction lines to eliminate vapor pockets, the line shall be laid in concrete trenches.

(2)The minimum clearance between the top of sleepers and the bottom of concrete trench shall be 75 mm.

(3)The clearance between the top of piping and bottom face of the trench cover shall be kept min. 50 mm.

2.16Sample Connection

(1)Liquid sample connections shall not be installed at the top or bottom of horizontal piping, nor located at the dead ends of piping.

(2)Gas sample connections shall be located at the top of a horizontal run piping or at the side of vertical piping.

(3)Sample piping shall be as short as possible.

2.17Utility Piping

(1)All branch piping from utility headers (steam, steam condensate, water, air, nitrogen, fuel gas, fuel oil, etc.) shall be taken from the top of the header to prevent plugging, however, water branch piping of 3" NPS and larger may be taken from the bottom of the header.

(2)If specified in P&ID and/or UFD, isolation valve onto branch line from steam header will be provided.

(3)Main steam line shall be provided with drip legs (boots).

(4)Steam distribution shall be comply with IP Refining Safety Code Part 3, Para. 9.1.2.2.

2.18Minimum Clearence 2.18.1 Minimum Clearence between Pipes/Valves

(1)For non-insulated piping, a minimum clearance of 25 mm shall be provided between the outside diameter of pipe flanges and adjacent pipes or a minimum clearance of 75 mm shall be provided between the outside surface of pipes. For insulated piping, the insulation thickness shall be taken into consideration.

(2)The minimum clearance between pipes which are subject to expansion and contraction shall be determined on a case-by-case basis.

(3)The minimum clearance between valve hand wheels shall be 75 mm

2.18.2For overhead piping, the following minimum vertical clearance between finished grade (or top of floor plate) and the bottom of piping, or support beam (whichever controls) shall be maintained :

(1)Over Roadway 5.0 m

(2) Pipe Rack (with truck access) 4.0 m

(3) Pipe Rack (without truck access) 3.0 m

(4) Above Walkways and Elevated Platform 2.1 m

2.18.3For access-ways, a minimum horizontal clearance of 600 mm shall be maintained.

2.18.4For sleeper piping, a minimum vertical clearance of 300 mm from grade shall be maintained.

2.19Pipe Through Floors

All piping that is to pass through the platforms or floors shall be passed through pipe holes. Size of the holes shall conform to the following table. However, efforts shall be exerted in the piping design to minimize the use of such arrangement.

Nominal Pipe SizeHole Diameter

An Insulated (mm)Insulated

1/2130When the piping is to be insulated, fractions of the insulation thickness shall be rounded off upwards and added to the pipe hole diameters

3/4130

1130

1-1/2150

2160

3190

4210

6270

8320

10370

12420

14460

16510

18560

20610

24710

3. PIPING AROUND EQUIPMENT 3.1Tower and Drum Piping

(1)Manholes and instruments of the towers and drums shall be provided on the maintenance side, while piping shall be arranged on the other side.

(2)Piping connected to towers shall, in principle, be arranged in consideration of facilitating easy supporting.

(3)Piping and their supports shall be arranged in consideration of thermal expansion of the tower and drum.

(4)Minimum clearance between the first stage platform and ground level shall be a minimum of 3 m.

(5)Platforms shall be arranged so that the vertical distance between upper and lower platforms does not exceed 8 m.

(6)In general platforms of 2,000 m/m - 3,000 m/m diameter shall be mounted on the top of the towers and vertical type drums. Width of the platforms shall be 1,000 m/m - 1,500 m/m where access is provided for manholes, valves, instruments, etc., and shall be 1,000 m/m where it is only for ladder landing. Spacing between the Platform and center- line of manholes shall be generally 700 m/m - 1,000 m/m and normally 800 m/m.

3.2Piping for Rotating Machines

(1)General

(a)Sufficient flexibility and adequate support shall be provided for piping which serves rotating machines, to minimize stresses applied on nozzles of the machine which might influence the proper installation alignment or internal clearances of the machine, or jeopardize the trouble-free operation of the machine.

(b)Connecting piping for rotating machines shall be arranged so that internal elements and casing sections of the machine can be removed for maintenance without interference with the connecting piping.

(2) Pumps

(a)Pumps suction piping shall be designed to avoid the formation of vapor pockets. Where a reducer is required in horizontal pump suction piping, an eccentric reducer shall be installed with the flat on top.

(b)The length of straight run pipe between elbow and pump suction nozzle in the horizontal suction lines of a double suction pump shall be at least 5 times the pipe diameter. Where a reducer is installed between a pump nozzle and a horizontal elbow in a pump suction line, the reducer shall be considered as a part of straight run pipe.

(c)Piping arrangement shall permit insertion and removal of permanent and temporary strainer internals without disturbing machine installation alignment.

(d)The design and location of permanent strainers shall be such as to permit cleaning without removing the strainer body.

(e)Type of strainers used in pump suction piping shall be as follows.

3" NPS and smaller size - Y type (Flanged connection).

4" NPS and larger size - T type (Butt weld connection).

T type strainer (Bathtub style)

(f)Strainer body material shall be applied corresponding to its piping material.

(g)Maximum efforts shall be made to locate the piping at the pump side for ease of maintenance work.

(h)All supports shall be of the adjustable type.

3)Compressor

(a)Special attention shall be given to reciprocating compressor , taking into consideration the effects of vibration and pressure pulsation, to prevent fatigue failure.

(b)The piping around compressor shall be arranged to prevent excessive force and moment effecting on to the nozzle.

3.3Heat Exchanger Piping

(1)Shell and tube heat exchanger

(a)Piping shall be arranged so as to allow removal of channel covers and tube bundle and give easy access for bolting.

(b)If practicable, symmetrical piping is desirable for the inlet piping of the heat exchangers having plural inlet nozzles.

(c)The configuration of piping connected to the respective heat exchangers of the same item arranged in parallel shall be symmetrical.

(d)Installing elevation are as below.

Note :

Foundation surfaces shall leveled where the heat exchangers are to be placed in low point.

(e)Locations of valves and orientations of thermometers around heat exchangers.

(f) Piping supports.

Adequate supports shall be provided to lines around heat exchangers.

(2)Air cooled heat exchanger

(a)All piping connecting to an air cooled heat exchanger, especially the inlet line, shall have sufficient flexibility and adequate support to ensure that, under no circumstance, the nozzles of the air cooled heat exchanger shall be subject to excessive stress and moment beyond allowable range.

(b)Piping around air cooled heat exchangers with multi-bundles, shall be arranged to ensure even flow distribution.

3.4Furnace Piping

(1)Arrangement of piping for burners shall be performed considering easy insertion and removal of firing torches, burners and burner guns. Furthermore, the piping shall not obstruct observation windows, access doors, header box covers and the tube removal area.

(2)The valves in the fuel supply piping to the burner and valves for steaming out, shall be located close to the furnace observation windows.

(3)Piping for multi-pass furnaces shall be arranged symmetrically, if no valves to adjust flow rate are provided in the piping.

(4)Surfing steam valves shall be located 15 m from furnace and consideration of facilitating quick access from the control room as well as ensuring a safe distance from the furnace.

3.5Tank Farm Piping

(1)Piping in tank dikes shall take the shortest possible route to the main pipe way, with appropriate allowance for expansion and contraction.

2)Piping shall be arranged to enable the absorption of nozzle displacement caused by tank settlement, or piping displacement caused by nozzle rotation due to tank shell deformation.

(3)Piping passing through dikes shall be adequately protected against external corrosion, and shall be capable of absorbing any possible movement of piping due to thermal expansion and contraction.

(4)Piping inside tank dikes shall not obstruct to heavy equipment's maneuver.

3.6Pipe way Piping

(1)In two-stage racks, utility piping shall preferably be installed on the upper stage and process piping on the lower stage.

(2)Large sized or heavy weight piping on racks shall primarily be laid on the sides.

(3)Reducers to be used on racks or sleepers shall be of the eccentric type to maintain constant elevation of the pipe bottom.

3.7Steam Trace Piping

Steam trace shall be designed in accordance with specification.

3.8Jacketed Piping 3.8.1 Jacketing methods

In cases where piping is to be jacketed, the entire piping system (including straight runs, fittings and valves) shall be jacketed.

3.8.2 Heating medium

(1)The heating medium to be used in jackets shall be steam normally.

(2)Steam shall be supplied from a point higher than the jacket and traps shall be provided at low points.

(3)Connection piping to jackets shall have the same size as that of the steam supply piping.

3.8.3 Precautions to be taken with respect to jacketed piping

(1)Since thermal stresses shall be caused by the differences in material and temperature between the inner and outer pipes in usual cases, consideration shall be given to this point.

(2)Expansion loops shall be used as a measure against excess stresses in the inner and outer pipes.

(3)No pockets shall be provided at the end of the process piping or at branches.

(4)Air pockets and drain pockets shall be avoided as far as practicable. In cases where they can not be avoided, vents or traps shall be provided.

4. PIPING DRAWING

4.1Process Unit

(1)Plan and each isometric drafting method shall be applied.

(2)For pipe rack and 1-1/2" and smaller C.S line in class 600 rating and lower piping, plan and partially detailed drafting method shall be applied

4.2Utility Unit Off-Site

(1)Plan and partially detail drafting method shall be applied.

4.3Scale

Scale shall be follows :

(1)Process Unit

(a)Plan drawing

1/60,1/50,1/30,1/25 or 1:33 1/3

(b)Partially details in the plan drawingNon scale

(c)Each isometric drawing

Non scale

(2)Off-site piping, Utility Unit, Pipe rack and Sleeper

(a)Plan drawing

1/30,1/50,1/60,1/100, 1/200,

1/25, 1:33 1/3

(b)Partially details in the plan drawingNon scale

4.4Letters

English shall be used for the drawing.

4.5Size of Drawings

A : 842 m/m x 1,189 m/m; for Plan Dwg. in principle

B : 594 m/m x 841 m/m; for Plan Dwg. supplementary

C : 420 m/m x 594 m/m; others

D : 297 m/m x 420 m/m; Each Isometric Dwg.

E : 210 m/m x 290 m/m; Support Dwg. Specifications and Other

APPENDIX I