The center line of the cam eccentric single seat is offset by the center line of the valve body a and B, and the seat sealing surface is eccentric B. When the stem rotates clockwise around the O point 90 degrees, the ball also rotates 90 degrees, and closely matches the seat sealing surface. When the friction torque between the sealing pair and the valve rod is greater than the torque formed by the medium pressure, the valve will be sealed reliably. Because the valve seal adopts cam eccentric structure, when the valve is opened, the ball quickly disappears from the seat cover. When the valve is closed, the ball quickly matches the sealing surface of the valve seat. So as to achieve the purpose of small opening torque and close closure.

Structural characteristics of hard sealed ball valve

Small caliber valve cavity space is narrow, and the usual structural design is no longer applicable. Therefore, the end of the stem is processed into a flat and short shaft with a flat groove and a hole on the top and bottom of the sphere. The hole is used to connect the ball with the upper and lower stem to the fixed sphere, to limit the degree of freedom of the sphere, and to balance the pressure between the body cavity and the medium of the pipeline. Slot with the stem with the flat, passing from the handle of the torque.

Manufacturing and processing of hard sealed ball valve

The tolerance of the two holes of the sphere and the eccentric size of the center line of the ball relative to the center line of the valve body are relatively strict. Generally, boring machines or CNC machine tools are needed. Before assembly, the front seat cover and the sphere face should be studied. Then the ball is placed in the closed position, the left valve body is installed, the gasket is adjusted, the screw is tightened, the static pressure irrigation does not leak, and the valve can ensure the seal under the seal test.

Conclusion of hard sealed ball valve

The small caliber hard sealed ball valve is in line with the relevant standards of the structure length, connection form and connection size of the ball valves at home and abroad. The valve is not only suitable for transporting gaseous or liquid single-phase medium, but also suitable for the medium of gas liquid mixed medium and gas-liquid mixture. The valve has been applied to metallurgical, textile and petroleum industries, and has achieved good results.