Plug valve overview

Plug valve: A valve with a through hole as a valve for the opening and closing member. The plug body rotates with the valve stem to achieve the opening and closing action. Small, non-filled plug valves are also known as "Cock". The plug body of the plug valve is mostly a cone (also has a cylinder), and cooperates with the conical hole surface of the valve body to form a seal pair. The plug valve is a valve that uses zui early, and has a simple structure, a quick switch, and a small fluid resistance. The ordinary plug valve is sealed by the direct contact between the finished 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, and can usually only be used for low (not higher than 1 MPa) and small. Caliber (less than 100 mm). In order to expand the range of application of the plug valve, many new structures have been developed. Oil lubricated plug valves are an important type of Zui (see [Oil Lubricated Plug Valves]). Special grease is injected from the top of the plug body between the cone hole of the valve body and the plug body to form an oil film to reduce the opening and closing torque and improve the sealing performance and service life. It has a working pressure of up to 64 MPa, a high operating temperature of 325 ° C, and a large diameter of 600 mm. The passage of the plug valve can take many forms. A common straight-through type is primarily used to shut off fluids. Three-way and four-way plug valves Suitable for the fluid-reversing plug valve, the opening and closing member is a perforated cylinder that rotates about an axis perpendicular to the passage to achieve the purpose of opening and closing the passage. Plug valves are primarily used to open and close pipes and equipment media. The main advantages of the plug valve are as follows: 1. It is suitable for frequent operation, quick opening and closing, and light. 2. The fluid resistance is small. 3, the structure is simple, relatively small volume, light weight, easy to repair. 4, good sealing performance 5, not limited by the installation direction, the flow of the medium can be arbitrary. 6, no vibration, low noise. The plug valve can be divided into four types according to the structure: a compact plug valve, a self-sealing plug valve, a stuffing plug valve and a oil-filled plug valve. By channel form