Leak Testing of Valves - Power Plant
Leak Testing of Valves - Power Plant
(OP)
When purchasing valves from a valve company is leak testing of valves by a supplier usual practice or a requirement of a standard? (Not pressure testing, just checking if there is any leakage over the valve seat at MAWP or MOP).
If it is normal practice to leak test valves, would it be satisfactory to test a full batch or only a sample.
On a separate point, has anybody any good or bad feedback on the following types of valve manufacturers:
Bollfilter
Bray
Camau
Friulco
Jasta
Krombach
LVF
Neway
S+S
Sisto
Zwick
If it is normal practice to leak test valves, would it be satisfactory to test a full batch or only a sample.
On a separate point, has anybody any good or bad feedback on the following types of valve manufacturers:
Bollfilter
Bray
Camau
Friulco
Jasta
Krombach
LVF
Neway
S+S
Sisto
Zwick





RE: Leak Testing of Valves - Power Plant
It is a normal practice to require API STD 598 compliance certification for seat leakage. Some project require testing a sample. Some may test all critical valves. Testing costs time and money. Neither leak testing nor certification assure that the valve won't leak after plant hydrostatic testing.
RE: Leak Testing of Valves - Power Plant
RE: Leak Testing of Valves - Power Plant
RE: Leak Testing of Valves - Power Plant
there are already discussions about the same issue within this Forum: see, for example, thread408-23297: Codes and Standards for leak testing valves and thread408-192222: Valve leakage.
About Zwick (and other Manufacturers of the same type of valve) please take a look at thread408-135872: The top three sellers for butterfly valve?.
Hope this helps, 'NGL
RE: Leak Testing of Valves - Power Plant
There are many standards for testing. "Bubble Tight" is not one of them although it is mentioned frequently and is completely meaningless unless a procedure is also involved.
Other useful specs are MSS-SP61 and API 6D.
FCI 70.2 is most frequently invoked for control valves but it is important to understand that 70.2 is merely a measure of the machining and assembly. The procedure (except for Class V) specifies testing at nominal 50 psi.
There is no relaible procedure to extrapolate what the leakage will be at other pressures, temperatures, or with other ladings.