the valve working under 6bar pressure air.
2007-03-23 03:59:22 · 3 answers · asked by RAJ K 1 in Science & Mathematics ➔ Engineering
The common solution is to use a gasket, for example an O-ring, leather, or compacted thread.
2007-03-23 06:46:46 · answer #1 · answered by snake_slinger 4 · 0⤊ 0⤋
Rubber O-rings are commonly used to seal butterfly valve stems having ratings to 150 psig, much higher than the 90 psg you need. If any leakage of the fluid is dangerous, than a special chamber can be incorporated into the design of the packing gland to be pressurized to 90 psig with a gas which is not dangerous and compatable with the fluid. Then size a compression spring for the gland to compress both O-rings to form the seal with both. So there will be two o-rings between a spring on the shaft- , one sealing the fluid from the chamber and one sealing the gas in the chamber from the room.
You will have reduced the leakage pressure of the fluid to the room to zero and any leakage of the gas is tolerable and can be monitored.
It is not likely that anything can be made fail prof, only fail resistant.
2007-03-23 22:08:02 · answer #2 · answered by Bomba 7 · 0⤊ 0⤋
No valve stem can be made absolutely leak proof. It is simply impossible. Just the mechanical operation of the valve over time will cause some very slight leakage.
2007-03-23 11:35:34 · answer #3 · answered by Controlfreak38 6 · 0⤊ 0⤋