What is a "Self Venting Plug"???
What is a "Self Venting Plug"???
(OP)
A Custumer ask me a Self Venting Plug on a valve equipped with low emission packing.
This Plug help to measure the lakage rate of the valve packing.
I really don't know that it is.
Do you know?
Thank you
This Plug help to measure the lakage rate of the valve packing.
I really don't know that it is.
Do you know?
Thank you





RE: What is a "Self Venting Plug"???
I believe that for ball valves you choose between single pistion or double pistion seats (for tunion mounted balls).
Best regards
Morten
RE: What is a "Self Venting Plug"???
Perhaps others call this option "Packing Flushing", as it allows to suck of flush the possible leakage away...
Hope this helps, 'NGL
RE: What is a "Self Venting Plug"???
I quote
"Ball valve design must ensure that excess pressure, resulting from expansion of liquid trapped in the ball and body cavity when the valve is closed, will relieve spontaneously in the direction of the higher line pressure. This relief may be accomplished by providing a relief hole in the ball, providing a passagein the body to the high pressure side, or by using cavity pressure self-relieving seats"
If your liquid has unusual thermal expansion properties perhaps thats what the client is aluding to.
Roy
RE: What is a "Self Venting Plug"???
However, the vented plug will NOT help measure the leakage of the valve packing.
A vented BONNET, with lantern ring double packing, WILL let you measure the packing leakage rate, because any leakage that gets through the bottom packing rings will flow out the bonnet vent where it can be measured and directed to a safe reclamation point. The upper packing set will keep anything from making it to the environment.