Function of check valve
The fluid resistance of swing check valve is generally less than that of lift check valve, which can be divided into three types: single disc swing, double disc swing and multi disc swing. Swing check valve is suitable for large caliber occasions. For the swing check valve larger than 80mm installed at the pump outlet, the horizontal installation method shall be adopted to reduce the valve disc seating and impact. For the pipeline with the diameter of the check valve at the pump outlet greater than or equal to 150 mm, the bypass shall be set before and after the check valve to prevent the damage to the sealing surface of the check valve caused by the high pressure rise in front of the valve.
The reason why the check valve does not work
- The check valve is installed reversely. It shows that the pipeline medium flows, and the check valve blocks the flow.
- Wrong selection or installation of check valve, such as vertical installation of check valve in vertical pipeline. For example, the flange connected lift check valve itself is installed vertically with the pipeline. The medium enters from the water inlet and pushes up the disc. The medium flows through the valve seat to another outlet of the check valve. The thrust to push the disc is less than the disc gravity, and the disc will fall naturally to the valve seat. If the valve is installed vertically, the gravity of the valve disc is all borne by the flange connected lift check valve, and the medium pushes the valve disc, only pushes the valve disc horizontally, and the valve disc cannot fall back to the valve seat naturally, causing the flange connected lift check valve to lose its function.
- The internal parts of the check valve are rusted. It is shown as the connection parts inside the swing check valve.
- The valve disc is not closed tightly due to the blockage of foreign matters
- Valve disc is broken or has sand hole.
- The check valves produced by Stv Valve Technology Group Co.,limited include swing check valve, lift check valve, ANSI check valve, DIN check valve, cast steel check valve, forged steel check valve and other materials.