The Float Valve Sub is usually connected on the top of the bit to control downhole liquid. While stopping pump and connecting with single, it can prevent waterhole from being plugged by reflowing drillings. When blowout occurrs, it can serve as splash valve to prevent liquid flowing into drilling tools.Its structure is divided into flapper type float sub and arrow-type float valve sub.
Construction
The Float Valve Sub consists of sub, float valve assembly and affiliated part. The Float Valve Assembly is including valve body, sealing ring, sealing sleeve, valve deck, torsional spring, limit mark. When operating, the bonnet of the float valve assembly will completely open, and it will close the waterhole while stopping pump and being blowout. It plays a role in blocking up the waterhole and preventing from blowout.
