| 摘要 |
A valve assembly to avoid or minimise the effect of "compression setting" which occurs when valves control the flow of some hazardous and/or corrosive fluids, especially when at en elevated temperature. The valve assembly includes a valve stem having a head portion which engages with a valve seat in order to close and seal the valve and an elastically deformable portion. In order to allow fluid to flow through the valve, the elastically deformable portion of the valve stem is deformed to allow fluid to pass between the head portion and the valve seat. An additional biasing element such as a cylindrical or conical compression spring is provided to urge the head portion towards contact with the valve seat. In this way, should "compression setting" of the elastic portion of the valve stem take place, the additional spring will ensure that the valve head is still able to be engaged with the valve seat to thereby close the valve.
|
