| 摘要 |
A piston valve assembly in which a piston member is outfitted with a plastic insulator between the metal piston member and a cover with which the piston member is otherwise engageable in one case and between the metal piston member and a valve actuator stem with which the piston member is otherwise engageable in another case, thereby preventing metal-to-metal contact therebetween and consequent metallic abrasion and pulverization.
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