| 摘要 |
1370254 Valves TK VALVE MFG Inc 1 May 1972 [10 May 1971] 20120/72 Heading F2V A seat for a ball or gate valve comprises a metallic ring 20 sealingly engaged in the valve body 10, which ring is spring biased towards the closure member and provided with an annular recess 26 which in turn accommodates an annular element 28 sealed within the recess and provided with a channel 38 to provide fluid communication from the body cavity 12 to the back side of the element. The element 28 may be made of plastics material, synthetic or natural rubber. When the valve is closed and the pressure is greater in the inlet, the inlet pressure acts on the back of the ring to maintain closure whereas when pressure is greater in the outlet 12, the closure is maintained by fluid pressure acting through the channel to the back of the element. |
