Which Is Better For Liquid Cooling Butterfly Valve: "low In, High Out" Or "high In, Low Out"?

Why are Butterfly Valve cooling designed with a low inlet and high outlet?

water cooling Butterfly Valve are designed with a low inlet and high outlet to minimize flow resistance and reduce force when opening the valve. Furthermore, when the valve is closed, the gasket between the valve body and bonnet and the packing around the valve stem are free of stress, preventing them from being subjected to prolonged pressure and temperature from the medium. This extends service life and reduces the chance of leakage. Furthermore, this design allows packing to be replaced or added while the valve is closed, facilitating maintenance.

Many people believe that water cooling Butterfly Valve are all designed with a low inlet and high outlet. This is not the case. Generally, cooling water Butterfly Valve are designed with a low inlet and high outlet. However, there are some special cases where a high inlet and low outlet are used:

1. High-pressure Butterfly Valve cooling system with a diameter greater than 100mm

Because large-diameter valves have poor sealing performance, this method is used to increase the sealing performance of water cooling Butterfly Valve when they are closed. The medium pressure acts above the disc when the valve is closed.

2. Two shut-off valves in series on the bypass pipeline: The second shut-off valve requires a "high inlet, low outlet" orientation.

To ensure valve tightness during a maintenance cycle, valves that are frequently opened and closed require two shut-off valves in series. For bypass systems, the installation of this bypass serves the following purposes:

① Balancing the pressure across the main pipeline valve, making opening easier and less labor-intensive, and reducing wear on the main pipeline valves;

② Warming up the pipes at a low flow rate during startup;

③ On the main feedwater pipeline, controlling the feedwater flow rate to control the boiler pressure rise rate for boiler water pressure testing. Bypass shut-off valves are divided into primary and secondary valves based on the flow direction of the medium. During normal unit operation, the primary and secondary valves are closed, and both are in direct contact with the medium. To protect the gasket between the secondary valve housing and bonnet and the packing around the valve stem from prolonged exposure to the medium and temperature, and to allow for replacement of the valve packing during operation, the secondary valve is required to be installed in a "high inlet, low outlet" orientation.

3. Boiler Exhaust and Vent Stop Valves

Boiler exhaust and vent stop valves are only used during boiler startup and water filling. They open and close infrequently, but they often cause fluid loss due to poor sealing. For this reason, some power plants install these stop valves in a "high inlet, low outlet" orientation to improve tightness.

4. Solenoid Quick-Stop Valves

The function of an electromagnetic quick-stop valve is to quickly close and quickly cut off the fuel supply. The structure of an electromagnetic quick-stop valve is similar to that of a stop valve. If the fluid enters the valve from the bottom and exits from the top, the fuel exerts a significant force on the lower disc of the electromagnetic quick-stop valve, while the weight of the electromagnetic quick-stop valve is much smaller. Therefore, if the fluid enters the quick-stop valve from the bottom, the torque generated by the weight is smaller than the torque generated by the fuel pressure. When the quick-stop valve actuates, the fuel supply cannot be cut off, thus defeating the intended purpose. If the working fluid enters the quick-break valve from the top, the downstream pressure drops rapidly once the quick-break valve is actuated, and the force exerted by the fuel on the lower portion of the disc quickly drops to zero. The force exerted by the fuel on the disc, combined with the weight of the weight and lever, is then combined.

Generally, for large diameters and high pressures, using a low-inlet, high-outlet configuration makes closing the valve difficult. If a low-inlet, high-outlet configuration is used for high-pressure, large-diameter applications, the valve stem is susceptible to deformation and bending due to long-term water pressure, compromising the valve's safety and sealing performance. Using a high-inlet, low-outlet configuration allows for a smaller stem diameter, saving costs for both the manufacturer and the user.