Check valve opening pressure

Won’t that lose the meaning of the design?

I heard there is a type of check valve that is slow-closing. I’ve only seen it in books; I don’t know if it actually exists. Or increase the flow velocity of the medium in the pipeline, or ensure continuous flow.

The main reason for the repeated knocking sound of the check valve’s disc is fluctuations in the actual fluid flow rate or an insufficient flow rate, which causes the disc to open and close frequently. The following solutions are recommended: 1. Check whether the flow rate is too low, resulting in insufficient opening pressure; the flow rate can be increased appropriately or a check valve with a lower opening pressure can be used. 2. Switch to a cushioned check valve equipped with a damping device (such as a slow-closing check valve) to reduce the opening and closing speed of the valve disc and prevent frequent impacts. 3. Add a surge tank or pressure stabilizing equipment before or after the check valve to reduce pressure fluctuations in the pipeline. 4. Adjust the operating conditions of the pump, such as increasing the discharge pressure or reducing the frequency of changes in the pump’s operating conditions, to ensure stable operation of the check valve. Under normal circumstances, the most effective solution is to replace or install a slow-closing check valve, which effectively prevents the valve disc from swinging and colliding frequently, thereby eliminating noise. .

What’s the meaning? What is the purpose of a check valve? You analyzed on your own that the noise comes from the back-and-forth movement of the valve plate; the question you raised was how to eliminate this noise……

This sound is not without use either; the gas pipeline can determine changes in gas flow velocity based on the frequency of its own sound. Increasing the pressure difference before and after the check valve can eliminate this noise; a low pressure difference makes it impossible to eliminate this pulsating flow.

Thank you for your suggestion; we’ll consider it

This phenomenon may be related to the installation type of the valve. It might be better if the fluid is installed flowing vertically upward, mainly to avoid the knocking phenomenon caused by a barely noticeable flow rate of the fluid. There are butterfly check valves available on the market, in which the internal valve disc closes naturally due to the action of a spring; this design basically prevents such phenomena from occurring. For reference.

Thank you for your suggestion; the check valve should be installed horizontally