pilot relief valve
先导溢流阀
先导式溢流阀
先导式水击泄压阀
先导安全阀
先导调压阀
导向排泄阀
溢流阀
bellows-operated pilot valve
change-over pilot valve
pilot operated safety valve
Pilot Valve
引示阀
液控单向阀
导引阀
试验井
导向阀
先导阀
导阀
指挥器
挤压点
导瓣
导井
前向导阀
sequenced pilot operated hydraulic control
sequenced pilot valve system
diaphragm operated valve
hydraulically operated valve
manually operated valve
pneumatic operated valve