Ball valve leak test

[metalonis]

Is there a standard for allowable leak rates during ball valve testing? I am looking for something similar to ANSL/FCI 70-2-1976, which is for control valves.

 

[JLSeagull]

Yes. I gather that you are addressing shutoff valves (bubble tight) instead of control valves (which leak like a sieve). You need a copy of API Standard 598, Valve Inspection and Testing. However, you should apply a valve specification that requires the bubble-tight leakage testing per API STD 598 before requiring the valve to comply.

 

[NGiLuzzu]

metalonis,
there have been several discussions about leak testing within this Forum already.

Probably you'll find what you need among the reference standards listed in thread408-23297 (in particular: API 598, EN 12266-1 and ISO 5208... pay attention to the edition dates, as the standards may have been revised in the meantime!).

But it must be observed that, unluckily, the most common standards about seat leakage testing of (on-off) valves usually refer to particular fixed test conditions, and to not take in account the influence of pressure, type of fluid and temperature on the leakage flow rates... so you may want to try, on your own, to adapt and/or extend the FCI-70-2 (or IEC 60534-4) concepts to on-off valves... and try to get your Customer ratiocinating on that (and this seems to be the hardest thing!!)! ;-)
About this issue, I'd suggest to see thread408-150132 and EN 1779 standard mentioned there.



In addition, maybe you'll find useful to take also a look at:

- thread408-76110 and thread174-76111 about the latest edition of the standard you mention;

- thread408-139863 and thread408-122060 about the FCI / IEC seat leakage classes;

- thread408-135434 and thread408-45258 about Class IV allowable leak rate calculation.



Hope this helps, 'NGL

 

[metalonis]

Thanks for the leads.