Ⅰ. Introduction of check valve
Check valve is an automatic valve. It relies on the pressure of the flowing medium in the pipeline to push the disc to close and open the valve. When the medium stops flowing, the check valve disc closes, it can be effective to prevent the medium in the pipeline from flowing back, which plays a great role in ensuring the safety of the pipeline.
Ⅱ. The installation position of the check valve
The check valve is installed to ensure the flow direction of the water flow inside the water pump, so as to ensure the normal operation of the water pump. Therefore, regarding the installation position of the non-return check valve, whether it is installed before the pump or after the pump, there are two situations:
- 1. One is installed at the end of the vertical suction pipe in front of the water pump, also called a bottom valve. The purpose is to fill the pump without pumping water once, because when there is no water in the pump and the suction pipe in front of the pump, the pump can only run idling and cannot pump water, so the pump must be filled with water to pump out water. The installation of this kind of water pump is a method when it is higher than the liquid level, also called negative pressure method.
- 2. The other is installed behind the pump. This installation method is that when the liquid level is higher than the water pump, it is convenient to start and stop the water pump without closing the water pump outlet valve, especially for the main control water pump system to prevent backflow.
The non-return check valve must be installed at the outlet of the pump and before the outlet control valve in order to check the check valve. Generally, the first outlet of the pump is the soft connection (shock absorber), the next is the check valve, and then the isolation valve (such as butterfly valve, gate valve, stop valve)
