valve leakage rating class standard

[ET1983]

Hi All,

To identify the leakage rate for all the valves, which standard to be reffered.? i had a confusion on whether to refer to API 598 / BS EN ISO 15848.

going through these standards, i understand that, ISO 15848 deals with stem seal leakages and API 598 deals valve seat leakages. hence, whether we need to specify both standards to the VENDOR for the leakage rate / classes.

 

[MickMc]

You are correct in that API 598 is related to general inspection and testing of valves whilst ISO 15848 is more concerned with fugitive emissions and possible leakage through stem packing. API 598 or equivalent is normally mandatory whilst ISO 15848 will depend on service and valve type.

 

[ET1983]

Thanks Mick.

So, in that case, for a Ball Valve, Floating type, (Considering a sour service fluid) it is not requried to indicate ISO 15848 leakage class, and shall be in accordance to API 598 leakage rates only. is that right?
Thanks.

 

[LittleInch]

See also ISO 5208 and this handy guide

http://www.google.co.uk/url?sa=t&rc...8ICgDQ&usg=AFQjCNGe5h71jK4fVoqDWZuhwWswoWMFPQ

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[MickMc]

Ball valves have stem and packing therefore susceptible to fugitive emissions although being quarter turn are superior in performance to rising stem valves such as gate and globe. In recent projects I have been involved only gate and globe in hydrocarbon and/or sour service have been subjected to this test at direction of owner and it is evolving subject these days.

 

[gerhardl]

All participants in this forum has a tendency to think that most valves in the world are produced and tested to US specifications, and used in petroleum related servicee . This might well be correct, but there are other specifications and tests (as illustrated in the original question) and other markets and requirements for certifications.

As all requiered tests are requiered by the end-user as a function of application, fluid and local regulations and rules, the most precise answer will be given when all details are known.

I can see situations where both tests (or one or the other) are requiered for all types of valves. If the question is a question of what tests should be incorporated as a standard in production for the general onshore (surface) worldwide petroleum market, answers given above
is in my opinion a good indication.