6 pound air test vs. 10 foot head water test?
6 pound air test vs. 10 foot head water test?
(OP)
I am not am not a Mechanical but have some limited experience. All of my work is in Civil. I have been proposed a question and am seeking some professional advice.
Is a 10-foot head water test comparable to a 6 pound air test for mechanical piping? The piping is located in an underfloor area. Additionally, are there cost benefits associated with the tests?
Is a 10-foot head water test comparable to a 6 pound air test for mechanical piping? The piping is located in an underfloor area. Additionally, are there cost benefits associated with the tests?





RE: 6 pound air test vs. 10 foot head water test?
If so, the answer is that the two pressures are close but not exact. 10 feet of water head is just over 4 psi (4.3 to be more precise).
The cost benefit as I see it is to find any leaks before everything is closed up and started up. Then, it's much more expensive to fix them.
Caution, I'm sort of a lurking process engineer so there 'may' be some code issues that I'm not familar with.
RE: 6 pound air test vs. 10 foot head water test?
Thanks!
Pete
P. J. (Pete) Chandler, PE
Mechanical, Piping, Thermal, Hydraulics
Processes Unlimited International, Inc.
Bakersfield, California USA
pjchandl@prou.com
RE: 6 pound air test vs. 10 foot head water test?
Suggest using water instead of air for static testing. Should there be a defect in system or a leak, the system pressure will rapidly decrease (not cause a lot of damage to surroundings) or leaks will easily be spotted. I know of a situation whereby a large pressure vessel was tested using nitrogen and a catastrophic failure occurred, resulting in signficant injuries to personnel and equipment. I know this does not answer your question, but something for you to consider.
pmover
RE: 6 pound air test vs. 10 foot head water test?
Note neither of these procedures constitute a "pressure test" as required by most piping Codes. The stress applied by either procedure is much too low compared to a 150% hydrotest or a 110% pneumatic test as required by ASME B31.3 for example.