Applications and characteristics of flow regulating and pressure regulating valves
The flow and pressure regulating valve is mainly composed of the valve body, piston, piston guide rail, built-in crank-slider mechanism, seal, internal parts, וכו. The main approach is to use a crank-slider to drive the piston to move, forming an axially symmetrical annular flow channel inside the valve body and effectively controlling the flow area. This results in a flow channel with a decreasing cross-section from the inlet to the outlet, gradually increasing the fluid velocity. Through the multiple holes in the circumferential direction, a jet collision is formed towards the center of the pipeline, thereby achieving the purpose of energy dissipation, pressure reduction, and flow regulation.
Summary
Under normal operating conditions, the flow and pressure regulating valve exhibits no jamming or harmful vibration, ensuring safe and reliable equipment operation. Its service life is no less than 30 years. The piston-type control valve has excellent anti-clogging capabilities and is suitable for fluids containing silt and small particulate impurities. Under large operating pressure differentials and dynamic water opening and closing conditions, the piston-type control valve ensures overall thrust resistance is safe and reliable, without harmful vibration.
The flow and pressure regulating valve is driven by a motor. The motor drive should have good waterproof performance, be flexible and reliable in operation, and the manual operating torque should meet national standards. The electric actuator of the piston-type control valve includes a motor, a reduction worm gear, a mechanical limit adjustment mechanism, a torque control mechanism, a stroke control mechanism, an opening indication mechanism, and a manual/electric conversion device. The electromechanical design of the piston-type control valve’s electric actuator is configured with a local operation control box.
Purpose
It is a multi-functional valve suitable for pipe network systems such as urban water supply, industrial water supply, mine water supply, power plants, water diversion projects, וכו. It can replace stop valves, pressure regulating valves, and flow regulating valves (one valve replaces multiple valves) at the same time. It plays the role of regulating flow, energy dissipation and evacuation, pressure reduction, and pressure regulation. It has excellent regulation and control functions for high pressure and large pressure difference conditions, and has the characteristics of energy dissipation, noise reduction, vibration reduction, and anti-cavitation. It can effectively improve system safety and reliability and meet system automation control requirements.
Function
The flow regulating and pressure regulating valve has three functions: it can adjust the flow, it can adjust the pressure, and the third function is to cut off the medium. The valve integrating these three functions replaces the gate valve and butterfly valve, saving nominal cost and installation space. It is mainly used in pipe network systems where the medium is water, such as water plants, power plants, and water diversion projects. It plays the role of regulating the flow rate and flow pattern of the pipe medium and regulating the pressure of the pipe network.
Advantages
1. Good linearity: Due to the special structural design inside the valve body, it has good linearity for the flow control characteristics of the fluid, and it still has good flow control effect even in the first 10% of the stroke.
2. Anti-cavitation and anti-vibration: Make full use of fluid dynamics principles to design flow channels to eliminate damage to the pipe network caused by cavitation and vibration, and greatly extend the service life of valves and pipelines.
3. Reliable operation: The reasonably designed flow channel and sealing type make the valve suitable for fluids containing small particles of impurities such as sediment, and will not cause leakage or control failure due to lax closing caused by impurities.
4. High-pressure energy dissipation: Even in the case of high-pressure difference, the valve can effectively eliminate high-pressure energy and reduce high-pressure to low pressure without causing vibration or cavitation, effectively ensuring the service life of the valve.
5. Excellent material selection: Key parts of the valve such as valve seats, blocks, guide rails and other components are made of special unreinforced materials. This material is wear-resistant, cavitation-resistant, and has three times the hardness of ordinary unreinforced materials.
6. Floating valve seat: The connection between the valve seat and the cone is bonded with special silicone, which has high viscosity and is resistant to shearing. The floating valve seat produces a self-centering effect when sealing, making the seal more reliable.
7. Small fluid resistance: The valve’s advanced structural design and reasonable flow channel distribution reduce the pressure loss of the entire valve to a minimum, which is beneficial to saving the power consumption of the entire pipeline network.
8. Small operating torque: The opening and closing parts in the valve are sleeve gates, whose movement direction is consistent with the flow direction of the main pipe fluid, and the effective force-bearing area is small, so the operating torque required to open and close the valve is also very small, and the cost of the driving device can be greatly reduced.
9. Long service life: The main seal in the valve is a metal pair, which is reliable, has strong resistance to fluid erosion, and is not easily damaged by mixed garbage. In addition, most parts are made of stainless steel, which greatly improves the service life of the valve.
