Float Valve is one of necessary tool for oil drilling, it consists of float valve sub and float valve, The main function are to prevent drill cuttings corne into mud when connecting each joint and the bit bore biock caused by back flow of silt. When the well blowout or kick, the valve cover of float valve turn off the bore automatically, it will prevent well blowout accident. Float valve sub has two types:
The Mode! F is a plunger-type float valve that provides a positive instantaneous shut off, providing constant fluid control while drilling. This plunger-type float valve is a reliable and economical sélection under standard drilling opérations.
The Model G is a flapper-type float valve that, when opened, offers an unobstructed bore through the float valve. The uniquely designed flapper closes rapidly to prevent shavings from entering the drill string when circulation stops and also assists primary BOP equipment in maintaining internai pressure control. The valve will fully open when the first joint is raised from the hole, preventing pulling wet joints.