| 摘要 |
A seal arrangement for a metering valve wherein a cylindrical member has a groove located on a face adjacent a seat which surrounds an opening connected to an inlet port. An elastomeric member has a base which is located in the groove with a projection that extends past the face on the cylindrical member. A ring is resiliently held against the elastomeric member by a sleeve to form a first static seal between the cylindrical member, retaining ring and sleeve. A piston located in the sleeve has a flange with first and second ribs thereon separated by a recess. An input member positions the piston such that the first rib engages the projection and compresses the elastomeric member before the second rib engages the seat to form a static seal between the piston and cylindrical member to assure that fluid flow between an inlet port and an exit port terminates when the piston is in a closure position. The recess on the piston provides a space for the elastomeric material to flow without damage to the projection when the first rib engages the ring and the second rib engages the seat.
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