Construction Procedure for Hydrotesting

8/10/2019 Construction Procedure for Hydrotesting

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CONSTRUCTIONPROCEDURE FOR

HYDROTESTING

SECTION CONTENTS

1.0 PURPOSE 2

2.0 SCOPE 2

3.0 REFERENCES 2

4.0 DEFINITIONS 2

5.0 GENERAL 2

6.0 PROCEDURES 3

7.0 TESTING OPERATIONS 5

8.0 TEST ACCEPTANCE 7

9.0 DEPRESSURIZING 8


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HYDROTESTING

1.0 PURPOSE

The purpose of this procedure is to ensure that Hydrostatic Testing is carried out in a safe manner

and complies with the requirements.

2.0 SCOPE

This procedure covers the activities and preparation required for Hydrostatic Testing for. This

procedure covers the Hydrostatic Testing for the mainline. All mainline valve assemblies shall be

hydrostatically tested independently.

3.0 REFERENCESThe following documents have been complied with in the preparation of this procedure!

"ontract #ocument $nformation.

A%&$'A&() * +1.8 , -as Transmission and #istribution Piping &ystems.

(alaysian -overnment egulation.

/ocal Authority egulations for removal and disposal of water used for testing.

4.0 DEFINITIONS

CLIENT !CONTRACTOR !

ST/!!P ! &uruhan0aya Tenaga'abatan eselamatan dan esihatan

SU"CONTRACTOR ! &ubcontractor'Party assigned by "3%TA"T3

to perform the Hydrostatic Testing activities

5.0 GENERAL

4.1 &T'P shall be notified a minimum of forty eight 5687 hours prior to the start of a

hydrotest operation. &T'P shall be invited to witness all hydrotesting with as much

notice as reasonably practicable. $n the absence of the &T'P epresentative a

competent -as )ngineer shall witness the testing.

4.2 All fields Hydrotesting reports shall be duly signed by the -as )ngineer and "lient and

&T'P such verification shall include signatures names dates and time.

6.0 PROCEDURES

6.1 C#$%&'&(

The cleaning operation is underta9en to remove any debris from the pipeline which may

have remained as a result of construction activities and to remove as far as feasible rust

mill scale which may be present on the pipe wall.


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HYDROTESTING

The cleaning operation will be conducted between temporary launcher and temporary

launcher' receiver. $t is proposed that one or two pig each consisting of high density foampigs and full circumferential wire brush high density foam pigs be propelled by

compressed air. The pigs will be controlled by regulating bac9 pressure to ensure a

speed of appro:imately ;.4 , 1.; m'sec.


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HYDROTESTING

water quality

sufficient quantity and flow rate

local authority permission to e:tract water from source

owners way leave

#etermination of water quality will be by visual inspection only. /aboratory

analysis chemical treatment etc is not required. The water for hydrostatic testing

should be visually free from sand silt and suspended solids.

The water source will be of sufficient quantity to enable the filling process to

proceed uninterrupted.

6.4 H+,*%*' T$* P+$-+$

The minimum test pressure at the point of ma:imum elevation for any test section shall

be 1.6 : design pressure i.e. 1.6 : +>; psig ? 4;6 psig 5minimum7

#epending on the site conditions the actual field test pressure may be raised slightly

higher than the minimum required hydrotest pressure as decided by the Test )ngineer.

6.5 P+$%+%*,+ ),+

All valves on the test manifolds that will not be used for the tests shall be blan9ed

off or plugged. =alves under test shall be left in the half open position.

$nstrumentation required for testing shall be set up in the test control cabin and

chec9ed.

Prior to the pressure test notices indicating that the pipeline is under pressure test are to

be stationed at strategic locations along the right of way. 5.3.@7 i.e. at all public

crossings and all points where there is e:posed pipe. &ubcontractor shall cordon of all

test end areas with notices stating that High Pressure Testing is in progressB.

/ine pipe of the same grade diameter and thic9ness as the pipe in the section under test

plus all the necessary equipment for handling transport cutting welding etc. shall be

available as a contingency in the event of a failure during the hydrostatic test.

Prior to any testing operations the stabiliCation of the test water temperature shall be

chec9ed.


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HYDROTESTING

pressuriCing rate after the stabilisation period. This process will be repeated at the

following points

; , 2; G of test pressure

2; , 4; G of test pressure

4; , 8; G of test pressure

8; , 1;; G of test pressure

&ubcontractor shall plot the pressure versus volume during the pressuriCing stage and

not made of starting and completion times. A temperature recorder and a deadweight

tester shall be operating during this time.


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HYDROTESTING

8.0 TEST ACCEPTANCE!.1 est "cceptance

Test pressure shall be maintained for a minimum of 26 continuous hours. Acceptance

shall be when the pressure changes while ta9ing into account temperature effects and

any 9nown lea9s does not e:ceed ;.1 bar for each ;.1" loss in temperature.

3n completion of the 26 hour test a Test Acceptance "ertificate approvals shall be

issued by &ubcontractor.

The test pressure was maintained for a minimum twenty four 5267 consecutive

hours at or above the minimum specified test pressure.

Any variation in test pressure during the 26 consecutive hours is e:plainable 5e.g.

temperature fluctuation7.

$f necessary the pressure changes attributed to the temperature effects on the pipeline

system under hydrostatic test shall be calculated and submitted to the "ontractor Test

)ngineer for approval.

!.2 est #ai$ures$f the test fails then the cause shall be investigated and remedied. &ubcontractor shall

then carry out the filling and testing operations again.

$f lea9age is apparent in the system a visual inspection shall be carried out at all above

ground pipewor9 and piping and valves in chambers. &hould a lea9 be detected it shall

be located and repaired and remar9ed in the hydrotest report form. $f the lea9 occurs in

the pipe seam or the pipe body the entire faulty 0oint for the pipe shall be cut out and

replaced with a new 0oint of pipe. $f the lea9 occurs in the circumferential weld the pipe

shall be cut one diameter bac9 either side of the faulty weld and replaced with a new

section shall be mar9ed with its location in the pipeline and shall be delivered to such

place as dictated by the "lient.

$f there is no lea9 found on the above ground pipewor9 the underground pipewor9 shall

be uncovered by bac9!hoe 5"*7 and a visual lea9 chec9 shall be carried out.

9.0 DEPRESSURIZING

$mmediately after the test has been successfully completed and the test acceptance certificates

signed by the relevant parties i.e. &ubcontractor Test )ngineer and "onstruction (anager

-(&* epresentative and &T the pressure shall then be gradually lowered to atmospheric

pressure at an appro:imately rate of F bar per minute.

Construction Procedure for Hydrotesting

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