| 摘要 |
A fire-safe rotary valve seat assembly for use in pressurized fluid systems subject to fire risk, the seat assembly having both a metal seat ring and an annular resilient non-metallic seal member to provide essentially zero fluid leakage at normal operating temperatures, and the metal seat ring to provide an extremely low rate of fluid leakage in the event high temperature should destroy the flexible seal member. The metal seat ring includes an annular groove around its radially inward face with a pair of flexible lips forming the walls of the groove, and the annular resilient seal member is mounted in the groove between the lips. The lips and the annular resilient seal member both engage a sealing surface on the circumference of a metal valve disc to provide a primary seal for the valve. If the annular resilient seal member is destroyed, the metal lips continue to provide an undamaged secondary seal.
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