valve
/vlv; vælv/ n
1 mechanical device for controlling the flow of air, liquid or gas in one direction only 阀; 阀门; 活门
the inlet/outlet valves of a petrol or steam engine 汽油发动机或蒸汽机的进给[排放]阀
the valve of a bicycle tyre 自行车胎的气嘴
a safety, exhaust valve 安全阀、 排气阀. =>illus at App 1 见附录1插图, page xiii. Cf 参看 tap1 1.
2 structure in the heart or in a blood-vessel allowing the blood to flow in one direction only （心脏或血管的）瓣膜.
3 device in certain brass musical instruments, eg cornets, for changing the pitch by changing the length of the column of air （管乐器的）活塞. =>illus at App 1 见附录1插图, page x.
4 (biology 生) each half of the hinged shell of oysters, mussels, etc 贝壳瓣. Cf 参看 bivalve.
5 = vacuum tube.