| 摘要 |
<p>A valve assembly is designed to avoid or minimise the effect of "compressio n setting" which occurs when valves control the flow of some hazardous and/or corrosive fluids, especially when at an 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 val ve 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 t o be engaged with the valve seat to thereby close the valve.</p> |
