Valve types and their appearance pictures - check valves

Check valves, also known as non-return valves, one-way valves or return valves, are valves used to prevent reverse flow of fluids. According to their structure and working principle, check valves can be divided into the following categories:

1. Lift check valve: The valve disc of this check valve moves vertically along the center line of the valve seat. The opening and closing strokes of the valve disc are short, suitable for smaller flow diameters. Its structure is relatively simple, but the flow resistance is relatively large.

2. Swing check valve: The valve disc rotates around the pin outside the valve seat. The flow resistance of the swing check valve is small, and the opening and closing are relatively fast, but the structure is relatively complex, and it is not suitable for fluids containing solid particles or with high viscosity.

3. Butterfly check valve: The valve disc is similar to the valve disc of the butterfly valve, and rotates around the pin outside the valve seat. The disc check valve has a compact structure and a small flow resistance.

4. Ball check valve: The valve disc is spherical and rotates around the valve seat. The ball check valve has a small flow resistance and opens and closes quickly

Ball check valve for slurry media.

5. The flow-limiting check valve is a special fluid control device with the following main functional characteristics:

Flow-limiting function: The flow-limiting check valve can accurately control the flow of fluid through the pipeline to ensure the stable operation of the fluid system. By adjusting the opening degree of the valve disc, the flow rate of the fluid can be effectively controlled.

Check function: When the fluid pressure decreases or the system has a backflow phenomenon, the flow-limiting check valve can automatically close to prevent the fluid from flowing back. This automatic closing function can effectively protect the equipment and pipelines from being damaged by the backflow of the fluid.

High stability: The design structure of the flow-limiting check valve makes it highly stable, able to operate stably for a long time, and ensure the normal operation of the fluid system.

The working principle of the flow-limiting check valve is based on the automatic adjustment of fluid pressure and valve disc. The specific process is as follows:

Fluid entry: When the fluid passes through the flow-limiting check valve, it will first act on the valve disc to generate a certain pressure.

Valve flap opening: As the fluid pressure increases, the valve flap will gradually open to allow the fluid to pass. The degree of opening of the valve flap determines the flow rate of the fluid.

Flow regulation: By controlling the degree of opening of the valve flap, the flow rate of the fluid can be accurately adjusted. The adjustment of the valve flap can be achieved by manual operation or by an automatic adjustment mechanism.

Automatic closing: When the fluid pressure decreases or the system has a backflow phenomenon, the valve flap will automatically close under the action of a spring or gravity to prevent the fluid from flowing back.

Flow limiting check valves are widely used in various fluid systems, especially in situations where it is necessary to accurately control the fluid flow and prevent backflow. The following are some common application scenarios:

Water heating system: In the water heating system, the flow limiting check valve can be used to control the size and direction of the water flow to ensure the stable operation of the system.

Industrial pipelines: In industrial pipelines, the flow limiting check valve can be used to control the flow of various fluids to prevent the backflow of fluids from causing damage to equipment and pipelines.

Fire protection system: In the fire protection system, the flow limiting check valve can prevent the backflow of fire extinguishing water to ensure the fire extinguishing effect and the normal operation of the system.

In summary, the flow-limiting check valve is an important fluid control device with the characteristics of flow limiting, non-return and high stability. By understanding its working principle and application scenarios, you can better select and use the flow-limiting check valve to ensure the normal operation of the fluid system.