testing of pressure pipelines -...

Testing ofPressure PipelinesJuly 2013

Table of Contents GL701-1.0 Introduction .................................................................................................... 1

GL701-2.0 Test Procedure Roles and Responsibilities .................................................... 1

GL701-3.0 Nomination of Test Method............................................................................. 1

GL701-4.0 Arranging a Test............................................................................................. 2

GL701-5.0 Test Equipment .............................................................................................. 2

GL701-6.0 Pre-Test Procedures ...................................................................................... 2

GL701-7.0 Methods of Testing......................................................................................... 4

GL701-Appendix A Test Selection

GL701-Appendix B Test Sheets

1

GL701-1.0 Introduction

Council requires infrastructure to be tested to ensure assets are:

a) Constructed to Council and manufacturers standards using good industry practice.

b) Complimentary to Councils existing infrastructure.

c) Fit for its required use and delivers the level of service Council is expected to provide the community.

The requirements of this guideline are set up to achieve these outcomes.

Where this guideline is silent on any issue, the requirements of Appendix C – Field Testing of Pipelines, NZS4404 shall apply.

GL701-2.0 Test Procedure Roles and Responsibilities

Unless approval is given by Council, the following parties shall attend all pressure tests:

a) The Contractor’s Representative – Representing the party responsible for constructing the infrastructure that’s being tested.

b) The Consent Holder's Representative or Engineer - Representing the party responsible for designing the infrastructure that’s being tested and monitoring the construction of it. The Consent Holder's Representative or Engineer is also responsible for nominating the test method, ensuring the correct test was carried out and the certifying the validity of the test results.

c) Council’s Approved Representative – Representing the party who will own the infrastructure that is being tested or has existing infrastructure that may be affected by the construction of it. This representative’s role is to witness that the testing is carried out as per the procedures in this guideline but is not responsible for certifying the test results.

GL701-3.0 Nomination of Test Method

It is the responsibility of the Consent Holder's Representative or Engineer to nominate the appropriate test method. This shall be done:

a) at the time of Development Works Approval when the detailed design is submitted to Council for subdivision work.

b) prior to release of tender for all Council Capital Works.

c) as agreed with the Team Leader: Water Supply for any other situations.

This allows for the testing method to be checked against the designed infrastructure to ensure the correct test method will be used.

Nominating the test method this early in the process ensures any discussions and agreements between parties are completed well before the time that the testing takes place.

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GL701-4.0 Arranging a Test

To arrange for a test to be undertaken, the procedures of IT-1 General Requirements for Inspections and Testing from the Infrastructure Development Code (IDC) shall be followed.

NOTE:

Requests to Council for testing of pipelines associated with subdivision projects shall be made to the assigned Development Engineer by the Consent Holder's Representative. Requests from any other party will be declined.

Requests to Council for testing of pipelines associated with Council projects shall be made to the assigned Council Project Manager by the Engineer. Requests from any other party will be declined.

GL701-5.0 Test Equipment

All test equipment shall be fit for purpose.

Council will supply 2 calibrated pressure gauges, a data-logger and a certified water meter for use during the test procedures. It has long been a concern that with various gauges being used in the field, consistent results have not been received over the years. Council are committed to ensure that infrastructure testing is carried out accurately and consistently and support this by supplying these measurement devices.

GL701-5.1 Use of Council Equipment

Council will provide its equipment when the timing for the test has been confirmed. The equipment shall only be used for the purpose it has been provided for and shall be returned immediately after the conclusion of the test procedure.

Where damage or loss of Council equipment occurs as a result of the actions of the Contractor and/or Consent Holder's Representative / Engineer, the Consent Holder's Representative / Engineer shall be responsible for reimbursement to Council for all costs incurred including full replacement if necessary.

All other equipment shall be supplied by the Contractor.

GL701-5.2 Use of Non-Council Equipment

In instances where the Contractor and/or Consent Holder's Representative / Engineer wish to use their own measuring devices, approval for this is required from the Team Leader: Water Services.

GL701-6.0 Pre-Test Procedures

The Contractor and Consent Holder's Representative / Engineer shall be familiar with the test procedure to be undertaken. All construction works relating to the infrastructure to be tested shall be satisfactory completed before initiating the final test with Council.

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The pre-test procedures are as follows:

a) All required temporary and permanent thrust blocks / thrust resisting methods (including joint restraint systems), shall be in place and all concrete shall be adequately cured (usually minimum of 7 days).

b) Blank flanges and/or caps shall be installed at the beginning and end of the test section. Testing shall not be made against closed valves unless they are fully restrained and it is possible to check for leakage past the valve seat. Mechanical ends that are not end load resistant shall be temporarily strutted or anchored to withstand the test pressures without movement.

NOTE:

Temporary supports should not be removed until the pipeline has been depressurised. All test personnel shall be informed of the loading limits on temporary fittings and supports.

c) Where practicable, all bolted joints shall be left exposed to allow for re-tensioning during and after testing.

d) Compacted embedment and fill material shall be placed to leave all joints, service connections and ball valves exposed wherever possible.

e) For PE pipelines, the pressurising time shall not exceed 45 minutes.

NOTE:

The pressurising time affects the duration of the PE pipeline test.

f) The test equipment shall be placed in position and checked for satisfactory operation.

g) The pump shall be of adequate size to raise and maintain the test pressure.

NOTE:

A pump that is too small may increase the test duration or where too large it may be difficult to control the pressure.

h) Two calibrated test gauges shall be used to cross check gauge accuracy.

i) Slowly fill the test length of pipeline with water, preferably from the lowest point, ensuring air is vented at the high point valves to just above atmospheric pressure. Allow a period, in the range of 3 hours to 24 hours, for the temperature of the test length and the test water to stabilise and for dissolved air to exit the system. The recommended rate of filling shall be based on a flow velocity of 0.05m/s, calculated as follows:

Qf 12.5 x D² Where: Qf = filling rate (litres / second) D = pipe diameter (m)

NOTE:

The slow rate of 0.05m/s avoids air entrapment when the filling water is cascading through downward gradients along the pipeline.

4

The period of stabilisation will depend on pipe dimensions, length, material, longitudinal profile and air exit points. For cement-mortar lined pipe, the pipeline shall be filled at least 24 hours before the commencement of the test to allow the lining to become saturated.

NOTE:

A firm foam swab may be used ahead of the fill water to assist air removal especially where the pipeline undulates. Extract the swab at a high-point wash-out.

GL701-7.0 Methods of Testing

The method of pressure testing is dependant on the pipe material, combination of materials and pipe pressure rating. Where the tested reticulation includes more than one pipe material, the appropriate test for each pipe material shall be undertaken independently i.e. 2 different pipe materials require a separate test for each

The test methods are:

a) Constant Pressure Test Method for Flexible Pipes

b) Constant Pressure Test Method for Visco-Elastic Pipes

c) Pressure Rebound Test Method for Visco-Elastic Pipes

d) Visual Pressure Test Method for Small Pipes The test method shall be selected using Table 1 Pipe Pressure Test Selection Guideline located in APX A Test Selection.

Where a pipe material is not included in the table or there is any uncertainty regarding the appropriate test to use for your situation, please contact Council for consideration and approval.

Where pressure measurements are not made at the lowest part of the test length, make an allowance for the static head from the lowest point of the pipeline and the point of measurement to ensure the test pressure is not exceeded at the lowest point.

GL701-7.1 Constant Pressure Test Method for Flexible Pipes

The specified test pressure (STP) = 25% above the rated pressure of the pipe material.

a) The procedure shall be as follows:

i) All pre-test requirements of GL701-4.0 Prior to Testing shall be undertaken and completed.

ii) All pipe lengths being tested shall have appropriate release points.

iii) All permanent inline valves within the test length shall be opened.

iv) Pressurise the test length to STP.

v) Maintain the test pressure by adding measured and recorded quantities of make-up water, at regular intervals over a period in the range of 1 – 12 hours.

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b) The amount of make-up water to maintain the test pressure shall be as per the following equation:

Q 0.14LDH

where:

Q = allowable make-up water (L/hr)

L = test length (km)

D = nominal diameter of the pipe being tested (m)

H = average test head over the length of the pipeline being tested (m)

c) The test length shall be accepted where:

i) There is no failure of any pipeline component e.g. thrust block, pipe, fitting, joint

ii) No physical leakage has occurred

iii) The amount of make-up water to maintain the test pressure complies with GL701-7.1 b).

GL701-7.2 Constant Pressure Test Method for Visco-Elastic Pipes






iv) Purge air from the pipeline.

v) Pressurise the test length to STP.

vi) Shut main off and let the pressure settle for 12 hours.

vii) Re-apply and maintain the test pressure for 5 hours by pumping a sufficient amount of water at appropriate intervals e.g. every 15 minutes.

viii) Record the water volume, in litres, required to maintain the pressure between Hour 2 and Hour 3. Meter readings shall be taken at 2 hours and 3 hours from the start i.e. from vii) above. The volume of water in measured in this timeframe is V1.

ix) Record the water volume, in litres, required to maintain the pressure between Hour 4 and Hour 5. Meter readings shall be taken at 4 hours and 5 hours from the start i.e. from vii) above. The volume of water in measured in this timeframe is V2.

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b) Calculate:

0.55V1 + Q.

where:

Q = allowable make up volume as per GL701-7.1 b).

c) The test length shall be accepted where:

i) There is no failure of any pipeline component e.g. thrust block, pipe, fitting, joint.

ii) No physical leakage has occurred.

iii) V2 0.55V1 + Q.

GL701-7.3 Pressure Rebound Test Method for Visco-Elastic Pipes


a) The first phase procedure shall be as follows: i) All pre-test requirements of GL701-4.0 Prior to Testing shall be undertaken and completed.



iv) Reduce the pressure to just above atmospheric pressure at the highest point of the test length and let it stand for 1 hour ensuring no air enters the line.

v) Raise the pressure to STP within 10 minutes. Hold this pressure for 30 minutes by pumping continuously, or for short intervals as required. Do not exceed the specified test pressure.

vi) During the 30 minute hold time, visually inspect for leaks. Shut off the pressure after this 30 minute period.

vii) Allow the pressure to drop for 1 hour.

viii) Measure the pressure after 1 hour (P60).

ix) If P60 70% of the STP, the test has failed. Locate and rectify the cause and repeat GL701-7.3a).

x) If P60 >70% of the STP proceed to GL701-7.3b).

b) The second phase procedure (air volume assessment) shall be as follows:

i) Within 5 minutes, reduce the pressure by 10-15% of STP ( P).

ii) Measure the water volume bled out ( V).

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iii) Calculate the maximum allowable volume using the following equation:

V(max allowable) = 1.2 x V x P((1 / Ew) + (D / e) / Er))

NOTE:

This equation differs from NZS4404.

Where:

1.2 = air allowance

V = pipe volume (L)

P = measured pressure drop (kPa)

Ew = bulk modulus of water (kPa) (see Table 1: Bulk Modulus of Water (Ew))

D = pipe internal diameter (m)

e = pipe wall thickness (m)

ER = pipe material modulus (kPa) (see Table 2: Pipe Material Modulus (ER))

Table 1: Bulk Modulus of Water (Ew)

Temperature (deg C)

Bulk Modulus (kPa x 103)

5 2080 10 2110 15 2140 20 2170 25 2210

30 2230

Table 2: Pipe Material Modulus (ER)

PE80B - E Modulus (kPa x 103) PE100 - E Modulus (kPa x 103) Temp (deg C) 3h 3h

5 680 900 10 610 820 15 550 750 20 510 680 25 470 630 30 430 600

c) If V > V(max allowable), the test has failed. Locate and rectify the cause and repeat GL701-7.3a) and GL701-7.3b).

d) If V V(max allowable), proceed to GL701-7.3c).

e) The third phase procedure (main test phase) shall be as follows:

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i) Record the pressure rise over 30 minutes.

ii) If there is a failure, locate and repairs leaks.

f) The test length shall be accepted where:



iii) The pressure rises or remains the same in the 30 minute time period.

NOTE:

If unsure about the pressure recovery, the length of monitoring time can be extended to 90 minutes. If the pressure drops by more than 20kPa during this period, the test fails.

GL701-7.4 Visual Pressure Test Method

Note: This test is not deemed by Council to be an acceptable minimum standard test. It shall only be undertaken after specific approval from Council is obtained.






iv) The STP shall be applied and the test length isolated by closing the high point release valves and the pump feed valve.

v) All joints, fittings, service connections and valves shall be visually inspected for leaks.

vi) Gauges shall be checked as an indicator that no undetected leak has occurred.

vii) Any leak shall be repaired and the test repeated.

viii) If no leak is found, the high point air release valves shall be opened and the pipeline slowly depressurised. All connection points shall be reinstated.

b) The test length shall be accepted where:



iii) There is no pressure loss indicating a leak.

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GL701-7.5 Post Test Procedures

After testing, pipelines shall be depressurised slowly. All air venting facilities shall be open when emptying pipelines. The test water shall be drained to an approved waterway and all connection points shall be reinstated.

GL701 - Appendix A Test Selection

GL701 - Appendix A.1 Selecting The Appropriate Test Method

Select the appropriate test method by using Table 3 Pipe Pressure Test Selection Guideline.

Where the tested reticulation includes more than one pipe material, the appropriate test for each pipe material shall be undertaken independently i.e. 2 different pipe materials require a separate test for each.

GL701 - Appendix A.2 Test Selection Guideline

Table 3: Pipe Pressure Test Selection

Test Method Pipe Material Pipe Diameter Test Sheet Further Criteria GL701-7.1 Constant Pressure Test Method (Flexible Pipes)

Flexible Pipes (PVC, DI, GRP, Steel)

Any Diameter TS7.1a

GL701-7.2 Constant Pressure Test Method (Visco- Elastic Pipes)

Visco-Elastic Pipes (PE, PP)

Greater than DN315

TS7.1b

GL701-7.3 Pressure Rebound Test Method (Visco-Elastic Pipes)

Visco-Elastic Pipes (PE, PP)

DN63 up to and including DN315

TS7.1c

C3.8 Visual Test Method

n/a Specific Council Approval Only

Note: PVC = Polyvinyl Chloride Pipe. DI = Ductile Iron Pipe. GRP =Glass Reinforced Plastic Pipe. PE = Polyethylene Pipe. PP = Polypropylene Pipe. Where a test length comprises different pressure ratings, the test shall be carried out to the lowest pressure rating in the test length. Where a pipe material is not included in the table, or there is any uncertainty regarding the appropriate test to use for your situation, please contact Council for consideration and approval.

GL701 - Appendix B Test Sheets

GL701 - Appendix B.1 Using The Appropriate Test Calculation Sheets

The following test sheets shall be used for each test procedure:

a) TS7.1a – Constant Pressure Test Method for Flexible Pipes.

b) TS7.1b - Constant Pressure Test Method for Visco-Elastic Pipes.

c) TS7.1c – Pressure Rebound Test Method for Visco-Elastic Pipes.

GL701 - Appendix B.2 Certification of Test Results

The following shall apply:

a) The test results sheet shall be certified, signed and dated by the Consent Holder's Representative or Engineer.

b) The test results sheet shall also be signed by the:

i) The Contractor’s Representative – representing the party who constructed the reticulation and performed the test procedures.

ii) Council’s Approved Representative – who witnessed that the test was carried out as per the correct procedures.

Date of Test: Resource Consent / TCC Contract No:

Development Name and Stage / TCC Contract Name

Project/ Pipe Location:

Contractors Reps Name: Contractors Company:

Certifying Engineers Name: Engineers Company:

Council Witness Name: Witnesses Company:

Pipe Material /Type: Pressure Rating (PN - bar) :

Length of Pipe Tested: (Km) = L

Max. Test Pressure (kPa) = 1.25 x PN :

Pipe Nominal Diameter: (m) = D

Ave. Test Pressure (m) = H :

Estimate or measure (To be supplied by the engineer prior to the test)

Pre-Test Checks Yes / NA

Ensure pre-test preparation acceptable and air purged from lineEnsure test section isolated & adequately supported against thrust

Time Meter Reading (L)

Start Time

Meter readings shall be taken Manual Calculation Space:at 15min or 30min intervals.Minimum test duration = 2hrsMaximum test duration = 5hrs

Measured Volume must be less than (L/15min)

Measured Volume must be less than (L/30min)

Measured Volume must be less than (L/hr)

Calculated Allowable Make Up Water - Q (L/hr)

Q=0.14*L*D*H

Is the Measured Volume of Make Up Water less than the Calculated Allowable Make Up Volume?

To Pass (a) = Y

The thrust blocks are acceptably in tact after test To Pass (b) = Y

There are no visible leaks. To Pass (c) = Y

I certify that this test was undertaken to the requirements of the Infrastructure Development Code

…………………………... (Contractor's Representative) …………………………... (Certifying Engineer)

I certify that I was in attendance during the testing procedure acting as a witness for Tauranga City Council

…………………………... (Council's Representative)

Overall Test Result:

Test Certification

Comment

Test Results

Target Calculated Volumes Of Make Up Water

Measured Volume of Make Up Water to Retain Test Pressure

Volume of Makeup Water (L)

Test Calculations

TS7.1a Constant Pressure Test Method for Flexible Pipes

(a) Y = Yes / N = No

(b) Y = Thrust Blocks OK / N = Unacceptable

(c) Y = No Leaks / N = leaks were detected

Test Establishment Information

Note 1bar = 10m = 100 kPa

3. Pressure logs shall be supplied to Council before full passing of test is recognised

2. Following the test measurement completion, all post test procedures outlined in NZS4404:2010 (Section C3.4) shall be completed

TS7.1a Constant Pressure Test Method for Flexible Pipes

1. Before starting the test, all pre-test procedures outlined in NZS4404:2010 (Section C3.3) shall be completed


Development Name and Stage / TCC Contract Name






Length of Pipe Tested: (Km) = L

Max. Test Pressure (kPa) = 1.25 x PN :

Pipe Nominal Diameter: (m) = D

Ave. Test Pressure (m) = H :

Estimate or measure (To be supplied by the engineer prior to the test)

Pre-Test Checks Yes / NAEnsure pre-test preparation acceptable and air purged from line

Ensure test section isolated & adequately supported against thrust

Apply test pressure , shut off, allow to settle over 12hrs

Time Meter Reading (L)

Start:

Reading at Hour 2:

Reading at Hour 3: (V1) = Makeup volume hour 2-3 (L)

Reading at Hour 4:

Reading at Hour 5: (V2) = Makeup volume hour 4-5 (L)

Calculate Q (L/hr) Q=0.14*L*D*H

Allowable Make Up Volume (L/hr) 0.55*V1 + Q (d)

Is V2 < Allowable makeup volume (d) ? To Pass (a) = Y







Test Results


Measured Volume of Make Up Water to Retain Test Pressure



Comment

TS7.1b Constant Pressure Test Method for Visco-Elastic Pipes


Test Certification


Volume of Makeup Water (L)

Test Calculations





TS7.1b Constant Pressure Test Method for Visco-Elastic Pipes


Development Name and Stage / TCC Contract Name:






Length of Pipe Tested: (m) = L

Max. Test Pressure (kPa) = 1.25 x PN: = P

Pipe Nominal Diameter: (m) = DN

Pipe Wall Thickness: (m) = e Refer TS7.1c Apx A

Pipe Internal Diameter: (m) = D

Pre-Test Checks Yes / NAEnsure pre-test preparation acceptable and air purged from lineEnsure test section isolated & adequately supported against thrust

(a)

(b)

Continue Fail

InitialMeter Reading

FinalMeter Reading

Volume of Water Bled (litres) V)

Pressure Drop (kPa) P)

Quickly (less than 5mins) reduce pressure by 10-15% of the standard test pressure (P), measure volume of water bled out.

Calculate volume of water in pipe V = x (D÷2)² x L x 1000 (litres)

(y)

Ew ...refer Table 1

Er ...refer Table 2

V(Max Allowable Bled) = 1.2 x V x P x ((1÷ Ew) + ((D ÷ e) ÷ Er)) (litres)

(x)

Continue Fail

Hold pressure at (P) for 30 minutes then cease pumping and allow to decay for 60 minutes

Reading of remaining pressure after 60 mins

Calculate 70% of test pressure (P)

If value (a) is greater than value (b), continue to next stage. If value (b) is greater than value (a), the test has failed.

If value (x) is greater than value (y), continue to next stage. If value (y) is greater than value (x), the test has failed.

Comment

Preliminary Phase Information

Air Volume Assessment



Raise pressure to test pressure (P) in less than 10 minutes - confirm test pressure

Reduce pressure and allow to stand for 60 mins to just above atmospheric at highest point

TS7.1c Pressure Rebound Test Method for Visco-Elastic Pipes

Time Pressure (kPa)

Is "Main Test Phase" pressure rise acceptable i.e. gradual, levelling after about 30 minutes?

To Pass (a) = Y







Data Tables for Air Volume Assessment

Temperature(°C)

51015202530

Temperature PE 80B - E Modulus (kPa x10³)

PE 100 - E Modulus (kPa

x10³)(°C) 3hr 3hr

5 680 90010 610 82015 550 75020 510 68025 470 63030 430 600

Test Results


Table 1 - Bulk Modulus of Water - Ew

Pressure Reading at Start Time

Pressure Reading after 30 minutes

Pressure Reading after ………… minutes

Pressure Reading after 90 minutes (if required)

TS7.1c Pressure Rebound Test Method for Visco-Elastic Pipes



Main Test Phase

Table 2 - Pipe Material Modulus - Er

(kPa x 10³)

2110

217022102230

2080


2140

Bulk Modulus




Test Certification

DN

MinO.D

(mm)

MaxO.D

(mm)MeanWall

MeanI.D.

MeanWall

MeanI.D.

MeanWall

MeanI.D.

MeanWall

MeanI.D.

63 63.0 63.6 - - - - 6.1 51.1 - -75 75.0 75.70 4.8 65.8 5.9 63.7 7.2 61.0 8.9 57.690 90.0 90.9 5.7 79.0 7.0 76.5 8.7 73.1 10.7 69.1110 110.0 111.00 7.0 96.5 8.6 93.3 10.5 89.4 13.0 84.5125 125.0 126.2 7.8 109.9 9.7 106.1 12.0 101.5 14.8 96.0140 140.0 141.30 8.8 123.1 10.9 118.8 13.4 113.9 16.6 107.6160 160.0 161.5 10.0 140.7 12.4 135.9 15.4 130.0 18.9 123.1180 180.0 181.70 11.3 158.3 14.0 152.8 17.3 146.3 21.2 138.5200 200.0 201.8 12.5 175.8 15.5 169.9 19.2 162.5 23.6 153.7225 225.0 227.10 14.1 197.8 17.5 191.1 21.6 182.9 26.5 173.1250 250.0 252.3 15.6 220.0 19.4 212.4 23.9 203.4 29.4 192.4280 280.0 282.60 17.5 246.3 21.7 237.9 26.7 227.8 33.0 215.3315 315.0 317.9 19.7 277.1 24.4 267.6 30.1 256.3 37.1 242.3355 355.0 358.20 22.2 311.1 27.5 301.6 33.9 288.8 41.7 273.2400 400.0 403.6 24.9 351.9 30.9 339.9 38.2 325.4 47.0 307.8450 450.0 454.10 28.1 395.9 34.8 382.4 43.0 366.1 52.8 346.5500 500.0 504.5 31.1 440.0 38.7 424.9 47.7 406.8 58.7 384.9560 560.0 565.00 34.9 492.7 43.3 475.9 53.4 455.8 66.1 430.3

Note: - The information above is taken from "Civil Plastic Pipeline Systems" (Poliplex) by Iplex Pipelines and isa guide only.

- All measurements are in millimetres (mm)

PN for PE100PN for PE80

TS7.1c Apx-A Polyethylene (PE) Pipe Dimensions

PN8PN10

PN10PN12.5

PN12.5PN16

PN16PN20

SDR17 SDR13.6 SDR11 SDR9

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