Check valve, also called rubber flap check valve, is an automatic valve. It relies on the pressure of the flowing medium in the pipeline to push the valve flap to close and open the valve. When the medium stops flowing, the rubber flap check valve flap closes. It can effectively prevent the medium in the pipeline from flowing back, which plays a role in ensuring the safety of the pipeline. Great effect.

According to the structure of the rubber flap check valve, it can be divided into three types: lift check valve, swing check valve and butterfly rubber flap check valve.

Lift check valves can be divided into two types: vertical and straight-through.

Swing check valves are divided into three types: single, double and multiple.

Butterfly check valve is divided into butterfly type double valve and butterfly type single valve.

The above rubber flap check valves can be divided into four types in connection form: threaded connection, flange connection, welding and wafer connection.

Installation location

The rubber flap check valve is installed to ensure the flow direction of the water flow inside the pump, so as to ensure the normal operation of the pump. Therefore, regarding the installation position of the check valve, whether it is installed before or after the water pump, there are two situations:

1 Install at the end of the vertical suction pipe in front of the pump

Also called the 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 not 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 above the liquid level, also called negative pressure method.

2 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 rubber flap check valve must be installed after the outlet of the pump and before the outlet control valve in order to check the valve. Generally, the first outlet of the pump is the soft connection (shock absorber), the next is the rubber flap check valve, and then the isolation valve (such as butterfly valve, gate valve, stop valve, etc.).