Today we will discuss the check valve installation location. So how to determine the installation position of the check valve? What is the difference between installing a check valve before the pump and installing it after the pump? Where is the installation in front of the pump suitable for? Check valves are usually used in conjunction with other valves, so when they are used in conjunction with other valves, where should the check valve be installed? Let’s discuss it together.
The check valve, also known as the non-return valve, is an automatic valve. It relies on the pressure of the flowing medium in the pipeline to push the valve flap to realize the closing and opening of the valve. When the medium stops flowing, the check valve flap is closed, and it can prevent The backflow of the medium in the pipeline plays a great role in ensuring the safety of the pipeline.
The purpose of installing the check valve is to ensure the flow direction of the water inside the pump, so as to ensure the normal operation of the pump, so the installation position of the check valve, whether it is installed before or after the pump, can be divided into two situations:
One is to install it at the end of the vertical suction pipe in front of the water pump. The purpose is to refill the water pump without pumping water once, because when there is no water in the water pump and the suction pipe in front of the pump, the water pump can only be idling and cannot pump water. It must be filled with water to pump out water. The installation of this pump is a method when it is above the liquid level, also called negative pressure method, such as pumping water from a well.
Another water pump installation method is that the liquid level is higher than the water pump. This method is generally used for secondary water supply. Since the liquid level is higher than the water pump, it is not necessary to close the water pump outlet valve when starting and stopping the water pump, so the check valve should be installed in the water pump. the rear.
The check valve must be installed at the pump outlet, before the outlet control valve, in order to access 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 next is the isolation valve (such as butterfly valve, gate valve, globe valve, etc.).
Advantages: It can protect the check valve, especially in parallel pumps, when one pump does not start and the other pump starts, the impact force is borne by the gate valve or butterfly valve.
Disadvantages: Who will protect the gate valve or check valve? There was a case where the disc of the butterfly valve was broken.
2. Install the gate valve or butterfly valve first and then install the check valve
Advantages: Butterfly valve or gate valve can be protected, and the impact force is borne by the check valve.
Disadvantages: Who will protect the check valve? The check valve is opened and closed by the pressure difference. If the pressure of the main pipe is high, it will be closed, and the pressure of the pump will be opened when the pressure of the pump is high. Affect the life of the check valve.
Post time: Sep-27-2022