stopcocks
n. 管闩( stopcock的名词复数 ); 活塞; 活栓; 旋塞阀
A stopcock is a tap on a pipe, which you turn in order to allow something to pass through the pipe or to stop it from passing through.
Plug stopcocks with sterile plugs.
在三通开关上塞上无菌塞子.