浮阀
浮阀通常安装在钻具接头的标准孔中，用以控制钻杆底部的液流。在停泵换钻杆时，浮阀还能防止切屑从钻头喷嘴中返回。
Float Valve
This Float
Valve is normally installed in
a standard bore-back of the bit sub, to provide fluid flow control at the
bottom of the drill stem. It also prevents backflow of
cuttings from plugging the
drill bit jets
while making connections.
