How a plug valve works

A valve with a plug body with a through hole as the opening and closing member. The plug body rotates with the valve stem to realize the opening and closing action. The small non-packed plug valve is also called "cock". The plug body of the plug valve is mostly a cone (also a cylinder), which cooperates with the conical hole surface of the valve body to form a sealing pair. Plug valve is one of the earliest valves with simple structure, fast switching and small fluid resistance. Ordinary plug valves are sealed by direct contact between the finely machined metal plug body and the valve body, so the sealing performance is poor, the opening and closing force is large, and it is easy to wear. Usually it can only be used for low pressure (not higher than 1 MPa) and small Caliber (less than 100 mm) occasions.