double thread hard seal butterfly valve  双线硬密封碟阀

hard sealing valve seat  硬密封阀座

Metal hard Seated Butterfly Valve  金属硬密封蝶阀

gas valve valve seat  气门-门座

valve-valve base  气门-气门座

Valve-valve seat  气门-气门座

Hard Roof and Hard Coal  两硬条件

Hard Roof and Hard Floor  坚硬顶底板

hard-soft-hard sandwich media  三明治介质

auxiliary valve relief valve setting  辅助阀安全阀调定

bell- shaped valve cup valve  钟形阀; 杯形阀

blade control valve relief valve  铲刀控制阀安全阀

brake valve relief valve  制动阀安全阀

butterfly valve + non-return intake valve  蝶阀+止回阀式进气阀

clack valve clap valve  蝶形阀

cooling valve charge relief valve pressure test  冷却阀加注安全阀压力试验

cup valve bell shaped valve  杯形阀; 钟形阀

cup valve(bell-shaped valve)  钟形阀; 杯形阀

dead-weight safety valve (weighted valve)  重码安全阀