The working principle of the drain cock is to rotate the valve stem to drive the plug body to rotate in the valve body, thereby controlling the opening, closing or regulating the flow of the fluid channel. The core of the plug valve is a rotatable plug with through holes of different shapes. When the plug rotates, the through holes will align or stagger with the pipeline, thereby realizing the on-off and flow regulation of the fluid.
Specifically, the structure of the drain cock (also known as the drain plug) includes a conical plug with a hole, which is inserted into the center hole of the valve body. When the hole of the plug is facing the inlet and outlet of the valve body, the fluid can pass through the plug; when the plug is rotated 90 degrees and its hole is blocked by the valve body, the fluid cannot pass through, thereby realizing the opening and closing effect. In addition, the operating torque of the plug valve is mainly determined by the friction between the valve seat and the plug, and is usually not affected by the fluid pressure.
Structural features The structural feature of the drain cock is that a rotatable conical plug with a hole is inserted into the center hole of the valve body. When the hole of the plug is facing the inlet and outlet of the valve body, the fluid can pass through the plug; when the plug turns 90 degrees and its hole is blocked by the valve body, the fluid cannot pass through, thus realizing the opening and closing effect. This design enables the drain cock to play both the opening and closing role and the regulating role.
Application scenarios
Drain cocks are widely used in water supply and drainage systems, petrochemical industry and gas transportation. In the water supply and drainage system, the drain cock can be opened and closed quickly, which is convenient for the inspection and maintenance of the pipeline and ensures the stable operation of the urban water system. In petrochemical production, the plug valve is used to transport corrosive chemical raw materials and flammable and explosive petroleum products with its good sealing and corrosion resistance. In the gas transmission pipeline, the oil seal design of the plug valve ensures the sealing and ensures the safety of gas transmission.
