Valve in hydrotest, is is allowed?

[Shashank Vagal]

Hi, Is it advisable to pressure test a water line for up to 10 bars with a valve already installed. (the valve will not be spaded during the test, it will only be in closed position)   Regards, Shashank Vagal

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[Rajneesh Gaur]

Mr. Shashank,

It will depend of the client requirements, and rating of the valve under consideration.

If the client asks for it to be done, it can be done provided the valve rating permits.

It would further prove the leak tightness of the valve or the quality of valve along with the line.

I have witnessed such hydro test.

 

Regards

Rajneesh

[Steven Ko]

Hi Shashank,

 

All valves install in the system had a design pressure that can withstand the normal hydrotesting practise of 1.5 times of the operation pressure shall be acceptable without causing any damage to the valve. Full bore valve shall in the half open position to had the body tested as well during testing and the rest can be tested together in the system.

 

Closed valve in testing system used as isolator only tested one side of it and its not acceptable.

 

Seat testing of valves installed in the system pressure testing system its not appropriate as the flow of pressure need to determine which side to be tested and site testing its sometime hard to achieve this.

 

All seat testing normal tested by using low pressure air test on high pressure side and held for couple of minute, sometime its need to be tested on both ends depend on valve type. High pressure testing do employ but its depending on type of valves used and requirement..

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Thanks you,

Best regards,
Steven Ko

email add:stev...@yahoo.com / steve...@gmail.com

[Rajneesh Gaur]

Mr. Shashank,

I agree with Steven, but it’s still a possibility if the client insists to do it. Although in normal cases we do not prefer to do it.

Secondly as far as rating is concerned if a valve is designed to withstand certain pressure, it is expected to withstand the without leaking in closed position.

As far as seat testing is concerned seat has to be tested from one/both sided at the manufacturer’s facility either by pneumatic or hydro testing. This again depends on the type, size and rating of valves e.g. flow control valves can be tested from one side as per flow direction (marked on the valves).   

The decision I believe depends on of the criticality of the job, type of valve and its intended application and the most important the client’s requirement.

 

Regards

Rajneesh

[Kristian Lund Jepsen (KUJ)]

My experience with this problem is that the valve manufacturer need to be asked.

I recently had such a case, where the valve manufacturer accepted the test pressure, but the test-duration (30 minuttes for the piping in that case) could not be accepted by the valve manufacturer.

 

Therefore, in the end, we had to set a plug in the valve inlet, to avoid pressure testing against the valve closing mechanisms themselves.

 

regards

Kristian

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From: material...@googlegroups.com [mailto:material...@googlegroups.com] On Behalf Of Rajneesh Gaur
Sent: 22. oktober 2009 08:28
To: material...@googlegroups.com
Subject: [MW:3534] RE: 3533] Re: 3531] Valve in hydrotest, is is allowed?

[Johnson Madukayil]

Valves have different leak classes. I think they go upto class V, with class V the most stringent. So even if the hydrotest is done, the valve may show some leak which could very well be within acceptable limits.

Regards

[Kristian Lund Jepsen (KUJ)]

Correct. Valves have (often) different leak classes. Those mentioned by Johnson Madakayil (class I, II,...V) is for control valves as per ANSI FCI 70-2.

 

On/off and check valves normally has the leakage rates specified in accordance with API 598, ISO 5208 or EN 12266-1. Here API 598 does not use leak classes. The ISO and the EN standard operates with leakage rates ranging from A (strongest requirement = zero leakage) to rate G weakest rate.

However, these leakage rates or classes are all for new valves being tested in the factory. After a valve has left the factory, it is probably not possible to have a valve to fulfil these factory acceptance tests. Valves that has been in use for some time may show much larger leakages than those specified/acceptance tested.

Regards

Kristian  

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From: material...@googlegroups.com [mailto:material...@googlegroups.com] On Behalf Of Johnson Madukayil
Sent: 25. oktober 2009 14:56
To: material...@googlegroups.com
Subject: [MW:3540] Re: 3534] RE: 3533] Re: 3531] Valve in hydrotest, is is allowed?

[Wayne]

Have just been doing research on this for a current project. Under ANSI/FCI 70-3-2004 the classes are listed to VII. It also shows the allowable leakage for the different size valves. Am currently having a disagreement with the client and engineer about a hydro test that dropped 9 PSI over a 4 hour period. The system dead ended at three valves (1-8" gate valve & 2-12" gate valves). There was no pressure on the back side of these valves and they are not accepting the test.

HELP !!!!!!!

Wayne

[Qasim Qayyum]

As per the testing in aramco specifications, valves can be used as an test limit if they are in closed position. If they are in-line valves, they must be removed.

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 With Best Regards

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QASIM QAYYUM,

Jazan Project,

Applus Velosi, KSA.

 

M 00966-59-0966115

[munee...@gmail.com]

Disagreement / Agreement without references for Acceptance / rejection is simply not acceptable.

Let your client submit his proof for rejection and you disagree or concur with your clause for acceptance.

Check the project specifications of your owenrs requirement.

Thanks.

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Regards,

Mohamed Muneeb Mahaboob

CSWIP 3.2-89247/2 & AWS-CWI (2007)

ASNT-NDT-L2-RTFI-RT-UT-MT-PT.

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E munee...@gmail.com M +91-636-955-7189

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