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Key points of structural design of pilot-operated Sleeve control valve

The pilot-operated sleeve control valve has been widely used in automatic control systems due to its small size, compact structure, good sealing effect, high shut-off capacity (up to nominal pressure), wide application range and long service life. . The valve can be used as a vent shut-off valve, especially for high temperature, high pressure and large-diameter shut-off applications.

The pilot-operated sleeve regulating valve has a top-down flow structure and a separate pressure-balanced pilot disc. As the valve closes, the pressure passes through the gap between the main disc and the sleeve to generate back pressure when the disc is closed, which is beneficial to the valve. When the pilot valve disc and the main valve disc meet the required specific pressure, the higher the medium pressure, the tighter the valve seal. When the valve is to be opened, let the actuator lift the valve stem and open the pilot valve disc first. Since the pilot valve disc has a greater flow capacity for the gap between the main disc and the sleeve, the main valve disc can be balanced, so as to be more efficient. A small force opens the main valve disc.

The design of the valve disc of the pilot-operated sleeve control valve should not only consider the closing performance of the valve, but also consider the stability performance and adjustment performance of the valve. The valve seat channel of the pilot valve should meet the flow capacity greater than the flow capacity of the guide ring and the gap between the main valve and the sleeve, and the opening degree of the valve should be controlled below 10% of the valve opening degree, otherwise the valve will not be opened or small. The problem that the flow range cannot be adjusted.

The design principle of the spring should be that the stiffness of the spring can resist the fluctuation of the medium pressure, otherwise there will be problems such as vibration between the pilot valve disc and the main valve disc.

The main function of the guide ring is to increase the stability of the disc assembly, and limit the problem that the gap flow capacity of the main disc and the sleeve designed for temperature reasons does not match the flow capacity of the pilot disc valve seat channel.

The function of the stop pin is to control the rotation trend of the pilot valve disc and the main valve disc due to eddy current, while the spring controls the upward and downward vibration trend of the pilot valve disc and the main valve disc.

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