double-ring_valve_有道手机词典

1.Metal cock ring soft seat surface pressure to the bearing surfaces, such as the valve core and valve seat is concentric ring surface can be a double tight closure.
金属旋塞表面压向阀座环软支座表面，如阀芯和阀座环表面是同心的，就能得到双重严密的关闭。
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