valven.瓣膜;真空管;阀门;电子管
valve rocker arm short spring气门摇臂短弹簧
valve rocker arm shaft spring阀摇臂轴弹簧
valve-seat grinding machine气门座研磨机
valve rocker arm shaft sleeve气门摇臂轴套
valve for petroleum equipment石油设备阀门
valve-controlled servomotor阀控制伺服电动机
valves used for power station发电站用阀
valve less piezoelectric pump无阀压电泵