What does a check valve do? Where are check valves used?

Check valve refers to the valve that automatically opens and closes the valve disc by relying on the flow of the medium itself to prevent the medium from backflowing, also known as check valve, check valve, reverse flow valve, and back pressure valve. The check valve is an automatic valve, and its main function is to prevent the backflow of the medium, prevent the pump and the drive motor from reversing, and the discharge of the container medium.

The accompanying drawing is a commonly used check valve shape and internal structure drawing.

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Here are some of the well-known brands recognized in the valve industry, which are widely recognized and have a high reputation. While rankings may vary depending on time and market conditions, the following brands are generally considered to be among the top brands in the valve industry:

The following are the top ten domestic first-line valve brand manufacturers in 2022-2023, but for reference only: Suzhou Neway Valve Co., Ltd., Shanghai Guanlong Valve Machinery, Shanghai Qizhong Valve Manufacturing, Sanhua, Su Yan, Shentong, Su Valve, Nanfang, Jiang.

First, the word Yao. The above manufacturers are only estimates and references, and the specific situation may vary or fluctuate at any time due to changes in a series of factors such as changes in the market, the size of the competition pattern, and the stability of product quality. As an indispensable key device in industrial production and civil facilities, the quality and reputation of the valve brand directly affect the satisfaction and trust of users.

These brands are known in the valve industry for their innovative technology, high-quality products and reliability. It is important to note that the market and industry are evolving rapidly, and different rankings may vary depending on time and region. For the most up-to-date ranking information, it is recommended to refer to industry reports, professional organizations or market research data for more detailed and accurate information.

Check valves are check valves that are used at the suction nozzle of water pumps.

Check valve belongs to the pipeline system accessories, is mainly used in a variety of pipeline fluid parts, its role is mainly three points, to prevent the medium backflow, to prevent the pump and drive motor from reversing, to vent the container medium, suitable for a variety of industrial pipelines and water supply and drainage systems, domestic water pipe network and other fields.

Check valves are often used in the following situations:

1. Water supply pipe network of high-rise buildings.

2. There is a certain chemically corrosive medium pipe network.

3. Sewage pipe network.

4. Water supply and drainage system.

5. Submersible, drainage, sewage pumps.

6. Domestic water pipe network.

7. Pipelines in petroleum, chemical, metallurgical and other industrial sectors.

Also known as check valve, it is an automatic valve, which relies on the pressure of the flowing medium in the pipeline to push the valve disc to achieve the closing and opening of the valve, when the medium stops flowing, the check valve disc is closed, and at the same time can prevent the medium in the pipeline from backflowing, which plays a great role in ensuring the safety of the pipeline.

The installation of the check valve is to ensure the flow direction of the water flow 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 in front of the pump or after the pump, can be divided into two situations:

One is to install the end of the vertical suction pipe in front of the water pump, the purpose is to fill the pump with water once without pumping water, because the pump can only idle and pump water when there is no water in the suction pipe in front of the pump, so the pump must be filled with water to pump out the water, the installation of this pump is a method when it is higher than the liquid level of Senhu, also called the negative pressure method, such as pumping water up from the well.

Another method of installing the pump is that the liquid level is higher than the pump, which is generally used when the secondary water supply is used, because the liquid level is higher than the pump in order to facilitate the start and stop of the pump, the pump outlet valve does not need to be closed, so the check valve should be installed at the rear of the pump.

The check valve must be installed at the outlet of the pump, in front of the outlet control valve, to allow access to the check valve. Generally, the first outlet of the Minchun pump is a soft connection (shock absorber), followed by a check valve, and then a partition valve (such as butterfly valve, gate valve, globe valve, etc.).

1. Install the check valve first, and then install the gate valve or butterfly valve.

Advantages: It can protect the check valve, especially in the parallel pump, 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 a butterfly valve was broken.

2. Install the gate valve or butterfly valve first and then install the check valve.

Advantages: It can protect butterfly valves or gate valves, 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 main pressure is high, the pump will be opened if the pressure is high, if the flow rate used is unstable, then the check valve will be repeatedly switched and closed, which will affect the life of the check valve.