Pressure Testing Open Ended Pipe

[MickMc]

We have an upcoming shutdown in Offshore Platform in Arabian Gulf and have open to atmosphere systems such as drains and vents.

I have experience of Operating Companies stating waiver to pressure testing within their own standards but cannot find any hard justification in any code except for Category D. Can anyone point me in right direction to be able to justify to client?

MickMc

 

[CJKruger]

For open ended pipes I typically use a design pressure of "Atmospheric" and then they don't get pressure tested.

 

[dcasto]

Why not put a blind in the header and test with air to 50 psig to assure all the header is tight.

 

[Ashereng]

If the pipe is open to atmospher, does it really matter if the header is not tight?


"Do not worry about your problems with mathematics, I assure you mine are far greater."
Albert Einstein
Have you read FAQ731-376 to make the best use of Eng-Tips Forums?

 

[vzeos]

Yes it matters. If there is a gas leak along a vent line passing through a confined space, you could get an accumulation in that confined space and cause an explosion hazard. It is best to insure the integrity of vent lines as dcasto suggests.

 

[Ashereng]

Fair point.

I was thinking most of the line would be outdoors on a platform. However, there may be the possibility that it is indoors as well.

"Do not worry about your problems with mathematics, I assure you mine are far greater."
Albert Einstein
Have you read FAQ731-376 to make the best use of Eng-Tips Forums?

 

[StressGuy]

I'll have to double check my memory on this one - But, as I recall, if the pipe is open ended, it is not pressure containing and is therefore not strictly subject to code requirements like pressure testing (at least as far as B31.3 is concerned)

Edward L. Klein
Pipe Stress Engineer
Houston, Texas

"All the world is a Spring"

All opinions expressed here are my own and not my company's.

 

[dcasto]

There is no requirment, but in an offshore platform, a leak check is a good idea. Remember, the pressure at the point of entry could be more than 25 psig during actual use. I would also assume that there will be purge gas entering the header at all times too.

 

[MickMc]

Thanks Guys for your prompt response.

My own view has been confirmed that as pressure is atmospheric and not pressure containing is not subject to pressure test under code. All systems will be subject to minimum of service test for leak examination.

 

[CJKruger]

MickMc,

Depend on what you mean by "service test". If it requires more than atmorpheric pressure, people will complain. And rightfully so, as you are instructing them to either (a) weld a cap or (b) install unnecessary flanges on the open ended pipe.

 

[vzeos]

They make test plugs for this purpose. Check out

http://www.mcmaster.com/

 

[RossABQ]

You could borrow a page from the plumbing side and do a static pressure test; i.e., fill it with water.