| 摘要 |
A valve having high and low pressure seals. The valve has a housing in which is mounted a valve closing member having a sealing surface which faces an opening in the housing. A low pressure seal surrounds the opening and is biased into contact with the sealing surface. A high pressure seal also surrounds the opening. Pressure in the valve pushes the closing member against the low pressure seal, which moves toward the opening until the closing member contacts the high pressure seal. |
