Characteristics and applications of check valves

Check valve is a kind of valve, which has the function of preventing the backflow of fluid. It consists of valve flap, valve seat, valve stem, spring and so on. The valve flap is located on the valve seat, and the function of the spring is to keep the valve flap in the closed state. When the fluid flows from the inlet to the outlet, the valve is pressed by the spring on the valve seat to prevent the fluid from flowing backwards. When the fluid flows from the outlet to the inlet, the valve flap by the fluid up, allowing the fluid to flow back.

Check valve features are mainly reflected in the following aspects:

Simple structure: check valve consists of valve flap, valve seat, valve stem, spring and other components, simple structure, easy to manufacture and maintenance.
Reliable: the working principle of the check valve is simple, reliable, not easy to fail.
Low price: check valves are inexpensive and have good economy.
Check valves are widely used in petroleum, chemical, metallurgy, electric power, water supply and drainage, construction and other industries. In the petroleum and chemical industries, check valves are used to prevent backflow of oil, chemicals and other fluids. In the metallurgical industry, check valves are used to prevent the backflow of metallurgical raw materials, metallurgical products and other fluids. In the electric power industry, check valves are used to prevent backflow of cooling water, lubricating oil and other fluids. In the water supply and drainage industry, check valves are used to prevent backflow of water, sewage and other fluids. In the construction industry, check valves are used to prevent air, water and other fluids backflow.

Check valve is a valve commonly used in the piping system, with good performance. Attention should be paid to the relevant requirements during installation, use and maintenance to ensure the normal operation of the check valve.

Classification of check valve

Check valves can be divided into the following categories according to the structural form:

Spring-loaded check valve: spring-loaded check valve is one of the most common types of check valves, consisting of valve flap, valve seat, valve stem, spring and other components.
Rotary check valve: rotary check valve valve flap and seat is rotary movement, driven by the valve stem.
Lift check valve: the valve flap and seat of lift check valve are in linear motion, driven by the valve stem.

According to the working principle can be divided into the following categories:

Gravity check valve: gravity check valve valve flap by gravity to keep in the closed position, driven by fluid pressure flap open.
Float check valve: float check valve valve valve flap by the float control, driven by fluid pressure flap open.
Pneumatic check valve: pneumatic check valve valve valve flap by air pressure control, by air pressure to promote the valve to open.

Selection of check valve

In the selection of check valves, should be selected according to the following factors:

Medium type: according to the type of medium flowing in the pipeline, select the appropriate valve body material and sealing material.
Working pressure: according to the working pressure in the pipeline, select the appropriate valve pressure level.
Operating temperature: according to the working temperature in the pipeline, select the appropriate valve temperature level.
Flow: according to the flow requirements in the pipeline, select the appropriate valve diameter and flow rate.
Transmission mode: according to the control requirements, select the appropriate transmission mode.

Check valve is a valve commonly used in piping systems, with good performance. In the selection of check valves, should be based on the actual need to select the appropriate type of valve and specifications.