短语词组短语guard van valve 车长阀guard s valve 车长阀turbine guard valve 水轮机保护阀guard s van valve 车长阀guard against error valve 保险阀guard 's van valve 车长阀;守车制动阀valve guard 阀箱;阀限位器;阀档板;阀片行程限制器delivery valve guard 吐出阀限位器 返回 guard valve