What are the uses and types of check valves？

The valve whose opening and closing parts (valve disc) automatically prevents the reverse flow of the medium by means of the force of the medium is called a check valve. In layman's terms, a check valve is an automatic valve that opens when the medium flows forward and closes when the medium flows countercurrently. This method of controlling the flow of the medium is used to prevent reverse flow of the medium, so that the pump maintains its initial state after shutdown, enables operation of reciprocating pumps and compressors, and prevents driving of backup rotary pump and compressor units in reverse. Check valves may also be used on lines supplying auxiliary systems where the pressure may rise above the primary system pressure.

In pipelines, check valves need to be installed wherever reverse flow of medium is not allowed. The parameter range of the check valve is as follows: nominal size DN10~1800; nominal pressure PN6~420; operating temperature t≤550℃.

There are many types of check valves, and the comprehensive classification is as follows: straight-through check valve, lift check valve, vertical check valve, single-disc check valve, double-disc check valve, multi-disc check valve, Single plate butterfly check valve, butterfly check valve, double plate butterfly check valve, conical diaphragm check valve, diaphragm check valve, annular braided diaphragm check valve.

Other typical check valve structures are shown in Figures 1-1~1-4

Figure 1-1 H72 high pressure wafer check valve

Figure 1-2 H41 type wafer check valve

Figure 1-3 Y-type DC check valve

Figure 1-4 H44 type swing rubber disc check valve