| 摘要 |
A seal for a reciprocating plunger is formed of a hard polyimide plastic, rather than the relatively soft elastomers of earlier seals. The present seal has a conical section, with the tapered face fitting closely within the mating conical face of a hard metal retainer. An O-ring resides in a groove within the seal to provide low pressure sealing between the plastic seal and the metal retainer. The tapers of the seal and retainer urge the seal inwardly toward the plunger by operational pressures, thereby providing a better seal. The present seal provides greatly extended life over softer prior art seals, and will generally last for the life of the pump or other mechanism in which it is installed. Yet, the plastic material allows some flow under high pressures, allowing the seal to conform closely to the plunger surface during operation and throughout the life of the seal.
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