Time duration for a pressure test 1

[raton]

Hi All.
Could anyone help me with this question?

How long should a pressure test last?

Is it reassonable that a pressure test lasts 15 minutes?

I cannot rememeber what ASME or BS PD5500 say about it and I would like to know if there is any standard that specifies 15 minutes.

On the other hand, is there any standard that requires to do the pressure test twice although the result of the first test was ok?
I was given a procedure where after the completion of the first pressurization, it has to come back to 0 bar and go up again to the test pressure.


Thank you very much

Jaime

 

[zdas04]

I did a reveiw of the literature on test duration for a safety manual chapter I participated in writing a few years ago (see Safety Manual ) and what it says still holds

Determining the length of a test, when a test should start, and if a test is successful has been the source of much discussion. Customs and regulations often specify test durations (e.g., static tests in several European countries are required to run for 24 hours after stabilizing). Sometimes local management sets the test duration (e.g., in some chemical plants, tests are required to be completed after 15 minutes). Absent regulation or local management requirements, ASME B31.8 specifies that tests should be held for 2 hours, but is silent on when the test actually starts. This is a critical omission because most procedures prohibit adding test media during the actual test. The test procedure should specify when the clock starts on the test. For hydrostatic tests, the start time should include an adequate delay for temperature to equilibrate and for dissolved gases to evolve from the water. For a gas test, a short time delay for temperature equilibration is necessary

David Simpson, PE
MuleShoe Engineering

http://www.muleshoe-eng.com

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

"It is always a poor idea to ask your Bridge Club for medical advice or a collection of geek engineers for legal advice"

 

[21121956]

Hello everybody:

raton, see the thread378-269828.

Good luck!

 

[mlanc]

According to MSS-SP99, a hydrostatic test performed on an instrument valve for proof pressure is on minute minimum. For burst test it is 15 seconds.

 

[raton]

Thank you very much guys.
It was a useful answer.
Much appreciatted.

jaime

 

[Cockroach]

Typically specified by the customer and spelled out on the purchase order, or dictated by a third party inspector. The industry typically calls for a chart 15 minutes in duration at maximum test pressure (1.5 MOP) at constant temperature.

I have charted for a half hour on ocassion. But fifteen minutes is extremely common.

Kenneth J Hueston, PEng
Principal
Sturni-Hueston Engineering Inc
Edmonton, Alberta Canada

 

[raton]

Thanks Cockroach,
Could you list any standard where 15 minutes are required?

Thanks

Jaime

 

[Cockroach]

API 6D 1991, pg 27 Table 5.2 displays the required minimum duration for hydrostatic shell and seat pressure testing.

In this regard, 15 minutes is the minimum allowable duration under the code for valve sizes NPS 12 thru 18.

Kenneth J Hueston, PEng
Principal
Sturni-Hueston Engineering Inc
Edmonton, Alberta Canada

 

[waterpipe]

I think it depends on the sector that you are working and the pipeline fluid.
For water main pipelines, AWWA M11 states:"the hydrostatic test pressure is usually applied for a period of 24 hours before the test is assumed to begin, principally to allow for a lining material to absorb as much water as is possible. after that, the pipeline should be carefully inspected for evidence of leakage. .... the test pressure should be maintained at least 2 hours."
M11 also specifies the permissible leakage rates.

 

[metengr]

How long should a pressure test last?

From a Codes and Standards perspective, the leak test duration should be as long as necessary to ensure no visible signs of leakage. This is common language and is up to the owner/engineer/inspector to decide. For example, a new power boiler 10 stories in height may take 30 minutes, a pipe spool, may take 2 minutes.