Check valves and their classification (brief overview)

Thread Content

Check valve: A check valve, also known as a one-way valve or non-return valve, serves to prevent the medium in the pipeline from flowing in reverse. The bottom valve at the water pump’s suction side also belongs to the category of check valves. A valve in which the closing element opens or closes on its own due to the flow of the medium and external force, in order to prevent backflow of the medium, is called a check valve. A check valve belongs to the category of automatic valves. It is primarily used in pipelines where fluid flow is unidirectional, allowing the fluid to move in only one direction in order to prevent accidents. Classified by structure, check valves can be divided into lift-type check valves, swing-type check valves, and butterfly check valves. Lifting check valves can be divided into vertical check valves and horizontal check valves. Swing check valves are divided into three types: single-disc check valves, double-disc check valves, and multi-disc check valves. Butterfly check valves are straight-through check valves. The aforementioned types of check valves can be classified, in terms of connection method, into thread-connected check valves, flange-connected check valves, and welded check valves. The following points should be considered when installing check valves: 1. Do not allow the check valve to bear any weight within the pipeline; large check valves should be supported independently so as to remain unaffected by the pressures generated by the piping system. 2. During installation, ensure that the direction of fluid flow is consistent with the arrow indicated on the valve body. 3. Lift-type vertical flap check valves should be installed on vertical pipes. 4. Lift-type horizontal disc check valves should be installed on horizontal pipes.