flap-type valve

• 瓣型阀门

flap-type valve的用法和样例：

例句

1. A needle valve with a threaded spindle is unscrewed to open a passage for the liquid to escape to the reservoir from the cylinder when the jack is required to be lowered.
   当千斤顶需要下降时，一个带锭子的针型阀门被放松来使液体通过圆筒流回储备液箱。