PSV Servicing/Testing Facilities

[Sharik]

There are PSV Test Stands being sold now which have a high pressure compressor feeding 1/2" tubing to the inlet of the PSV. These are being sold as certified for testing all sizes of PSV, via an adjustible clamp/flange assembly.

This is quite different than what I'm used to. I've always used a Test Bench with a large receiver so that there was enough volume to actually pop open all the PSV's up to the maximum set pressures and PSV inlet sizes as authorized in the organizations PSV QC Program.

Are these PSV Test Stands with pressure and without volume, acceptable for testing 'UV' stamped PSV's? Is it acceptable to just simmer a PSV when testing or is it mandatory to pop the PSV 100% open?

 

[gerhardl]

Should be interesting to see a copy (in English) of the exact text you are referring to. What does the 'certification paper' for the test bench say, and what authority has issued the certification? Do the text just mention 'all' or is it referring or giving exact references to certification and test standards allowed to be performed in this bench, with references to sizes, types and pressures for valves?

I think you will find your answer by cross referring with the exact test prescriptions/regulations you are wanting to certify to. This will decide, not what is (wrongly or rightly) mentioned in the test bench papers.

 

[Sharik]

There are no single certificates on these test benches which indicate approval by ASME, API, NB, ISO, etc. All the components of the test stand (valves, guages, electrical, etc.) have certificates indicating they conform to a Standard. The brochures indicate only the maximum pressures and just how easy it is to clamp any size PSV to the bench.

Attached is a sample of the bench and a close up of where the PSV's are clamped to the bench flange. You can see there is only a 1/2" tube feeding to the inlet of the PSV. How can thie meet the requirements of API 576 and how can this possibly pop open a 2" and larger PSV?

 

[gerhardl]

To clarify, and I think it is as simple as that: If the test bench is not able to correctly do all operations necessary to do what is required by the described test procedures given for testing, it is not suitable or allowed for this testing. If the supplier can not guarantee what is necessary for your test, you are on your own.

 

[Sharik]

But what are the testing requirements? Is full opening 'popping' required or is it acceptable to just simmer a safety valve? For ASME stamped PSV's, must the test bench meet the requirements in API 576 ( 12" diameter, 72" long receiver with at least a 6" NPS test flange connection) or is a 1/2" tube from a HP compressor sufficient? I know if it was a newly designed PSV, the testing requirements are much different as not only set pressure but relieving capacities must be verified. But what about the recertifying pop tests completed on PSV's after servicing? Things seem to be different as to what is done in most of North America compared to other areas of the world.

 

[gerhardl]

I am a Scandinavian citizen without the detailed US knowledge you need. Your question would stand a better chance of proper answer rephrased and posted on the safety valve forum. Good Luck!