API 6D Valve Leak Rate

[Pern1971]

I have some valves that are leaking under approx 80 psig. They are 3" steel ball valves with a PFE seat, 1/4 turn with a stainless full port ball. The spec sheet says they are designed to API 6D and were tested with API 598. What is the designed leakage rate from new? Where would I find the API specs on this? thx!

 

[Ripz]

API-598 Table 5.

 

[EnergyMix]

The standards are available from the American Petroleum Institute (

http://www.api.org/).

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[Roberto1956]

If you go to API 598 you will find high pressure test with water at 1.1 x rating pressure as ASME B-16.34, low pneumatic test at 5 bar and very low pneumatic test 0,5 bar (this last one is supplementary).
My default to buy the valves is high pressure test wit water and low teste with air EVER.

 

[JohnGP]

Pern1971, I note that you indicate your valves are designed to API 6D, if constructed to that standard then 6D requires that there be no visible leakage during tests for such soft seated valves. I understand API 598 has similar criteria.
Cheers,
John

 

[Dean8573]

API 6D and API 598 both call for a tight shut off if the valve is soft seated, the leakage rate differs between the specifications when you move to metal seat designs. the preesure you work to will depend on class rating, as mentioned above both the API specs refrence B16:34 for pressures based on a material basis. Please take note that both the API standards are factory acceptance standards are nul-invoid if the valve has been subject to service.