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Eccentric hemispherical valve



Eccentric hemispherical valve

Eccentric hemispherical valve is a relatively new type of ball valve, which has some unique advantages of its own structure, such as the switch without friction, the seal is not easy to wear, and the opening and closing torque is small. This will reduce the specifications of the actuators fitted. Equipped with multi-turn electric actuators, it can realize media adjustment and strict close. Widely used in petroleum, chemical, urban water supply and drainage and other conditions require strict cut off.


Eccentric hemispherical valve features:

  1 eccentric hemispherical valve is a top-mounted structure. The valve installed on the pipeline can be directly checked and maintained online, which can effectively reduce the parking of the equipment and reduce the cost.

  2 Eccentric hemispherical valves are single-seat designs. Eliminates the problem that the medium in the cavity of the valve will affect the safety of use due to abnormal pressure rise. The

  3 low torque design. Specially designed valve stems can be opened and closed easily with a small hand.

  4 open and close without friction. This function completely solves the problem of traditional seals that are affected by friction between the sealing surfaces.

  5 wedge seal structure. The valve is based on the mechanical force provided by the valve stem and presses the ball wedge onto the valve seat to seal the valve, so that the valve's tightness is not affected by the pressure difference of the pipeline. The sealing performance is guaranteed under various working conditions.

  6 Eccentric hemispherical valve sealing surface self-cleaning structure. When the ball is tilted away from the valve seat, the fluid in the pipeline passes through 360° along the sealing surface of the ball, which not only eliminates the erosion of the valve seat by high-speed fluid, but also removes the accumulated material on the sealing surface to achieve the purpose of self-cleaning. .

  Eccentric hemispherical valve knowledge overview: Eccentric hemispherical valve with cutting function

  1. The eccentric hemispherical valve consists of valve body, eccentric shaft, valve cover, spherical cap, shaft sleeve, valve seat and other major components. The eccentric shaft rotates by 90° to open and close the valve, which acts as a truncated medium.

  2. The eccentric hemispherical valve ensures that the valve seat and the spherical cap do not rub against each other when the valve is opened or closed. The eccentric hemispherical valve adopts an eccentric crankshaft, which deviates from the center line of the valve flow passage by an eccentricity. When the valve is opened, the crankshaft rotates through a very small angle, the crown will leave the valve seat, and the spherical cap and the valve seat will no longer be in contact; otherwise, during the closing of the valve, the ball cap and the valve seat will only be closed at the moment of closure. contact.

  3, eccentric hemispherical valve adopts the top-mounted structure, in the maintenance process, do not need to remove from the pipeline, just remove the bolt on the valve cover, remove the valve cover, which can remove the eccentric shaft, so that the valve can be online service.

  4. The eccentric hemispherical valve should ensure that the flow path is completely open when it is opened, and the head loss is small during operation. The ball adopts a semi-circular channel, which has good flowability and linear adjustment performance, and impurities are not deposited in the cavity of the valve body.

  5, eccentric hemispherical valve should have sufficient strength, eccentric crankshaft using a fixed ball structure, without any vibration at high flow rates, shell test according to our national standard GB13927-1992 implementation.

  6. Eccentric hemispherical valves are not allowed to have external leakage. The upper and lower shaft ends should be sealed with at least two O-ring seals.

  7. The eccentric hemispherical valve has a cutting function. When it is closed, it can cut off the sundries (branches, textile bags, etc.) in the medium to ensure the normal opening and closing of the valve.