The square drill pipe cock is also called the square drill pipe cock or the drill pipe safety valve. It is a manual control valve in the drill string circulation system and one of the effective tools to prevent blowout. The square drill pipe plug valve is divided into the upper square drill pipe plug valve and the lower square drill pipe plug valve. The upper square drill pipe plug valve is used between the lower end of the tap joint and the kelly. The lower square drill pipe plug valve is used between the lower end of the square drill pipe and the upper end of the drill pipe, and the switch can be realized by turning 90° with a special wrench according to the instructions. In drilling operations, in order to avoid the occurrence of vicious accidents, kelly plug valves should be assembled at the upper and lower ends of the kelly to prevent the loss of drilling fluid and prevent blowout.
