The use and structural characteristics of the double petal butterfly check valve

In order to prevent the backflow of the medium, check valves should be installed on the equipment, fixtures and pipelines.

The main features of the double-flap butterfly check valve are:

1. The structural length of the double-petal butterfly check valve is short, and its structural length is only 1 4 1 8 of the traditional flange check valve;

2. Small size, light weight, its weight is only 1 4 1 20 of the traditional flange check valve;

3. The valve disc of the double-petal butterfly check valve closes quickly, and the water hammer pressure is small;

4. Both horizontal and vertical pipelines can be used, and the installation is convenient;

5. The double-petal butterfly check valve flows smoothly and the fluid resistance is small;

6. Sensitive action and good sealing performance;

7. The disc stroke of the double-petal butterfly check valve is short and the impact force is small;

8. The overall structure is simple and compact, and the shape is beautiful;

9. Long service life and high reliability.

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 influential first-line brands of water system valves and industrial valves can be used as a reference, but for reference only: Suzhou Neway Valve, Shanghai Guanlong Valve, Shanghai Qizhong Valve, 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.

The working characteristics of the check valve are that the load changes greatly, the opening and closing frequency is small, and the application cycle is very long as it is put into the closed or open state, and it does not require the movement of moving parts. However, once there is a "switching" requirement, it must be moved flexibly, which is more demanding than the usual mechanical movements. Since the check valve is qualitatively determined to be used for rapid closing in most practical uses, and at the moment when the check valve is closed, the medium flows in the direction of the disc, and with the closure of the valve disc, the medium rapidly decreases from the maximum reverse flow speed to zero, while the pressure rises rapidly, that is, the "water hammer" phenomenon that may have a destructive effect on the pipeline system is generated.

For high-pressure piping systems where multiple pumps are connected in parallel, the problem of water hammer on check valves is even more prominent. Water hammer is a kind of pressure wave in the transient flow in the pressure pipeline, which is the hydraulic shock phenomenon caused by the change of the fluid flow rate in the pressure pipeline. The physical cause is the combined effect of the incompressibility of the fluid, the inertia of the fluid motion and the elasticity of the pipeline.

In order to prevent the hidden danger of water hammer in the pipeline, over the years, people have adopted some new structures and new materials in the design of the check valve, and gratifying progress has been made in reducing the impact force of the water hammer to a minimum while ensuring the applicable performance of the check valve. 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.

Check valves can also be used on lines that supply auxiliary systems where pressure may rise above the system pressure. Check valves can be mainly divided into swing-type check valves (rotating according to the center of gravity) and lifting check valves (moving along the axis).

Structural features of butterfly check valves1. Small size, light weight, compact structure and easy maintenance.

2. The valve plate adopts the design of adding two torsion springs on the dual plate, which can make the valve plate close quickly.

3. Due to the quick closing effect, it can prevent the backflow of the medium and eliminate the strong water hammer effect.

4. The length of the valve body structure is small and the rigidity is good.

5. It is easy to install, and can be installed on the pipeline in both horizontal and vertical directions.

6. Achieve complete sealing, and the leakage of the hydrostatic test is zero.

7. Safe and reliable performance and good anti-interference.

1. The structure of the lifting check valve is generally similar to that of the globe valve, and its disc moves up and down along the center line of the channel, which is reliable in action, but the fluid resistance is large, and it is suitable for smaller diameter occasions. The lifting check valve can rotate around the rotating shaft of the valve disc of the air straight-through and 2, rotary check valve. Its fluid resistance is generally less than that of the lifting check valve, and it is suitable for larger diameter occasions.

According to the number of valve discs, it can be divided into three types: single-lobe swing type, double valve swing type and multi-valve swing type. Single-flap swing check valves are generally suitable for medium caliber applications. When a single-valve swing-open check valve is selected for large-diameter pipelines, it is best to use a slow-closing check valve that can reduce the water hammer pressure in order to reduce the water hammer pressure.

The double-valve check valve is suitable for large and medium diameter pipelines. The double-valve swing-open check valve has a small structure and light weight, and is a fast-developing check valve; Multi-lobe check valves are suitable for large-diameter pipelines; 3. The structure of the butterfly check valve is similar to that of the butterfly valve, with simple structure, small flow resistance and small water hammer pressure; 4. Diaphragm check valve has a variety of structural forms, all of which use diaphragm as opening and closing parts, due to its good waterproof performance, simple structure and low cost, it has developed rapidly in recent years, but the use temperature and pressure of diaphragm check valve are limited by diaphragm materials;

Structural features:

1. The structural length is short, and its structural length is only 1 4 1 8 of the traditional flange check valve

2. Small size, light weight, its weight is only 1 4 1 20 of the traditional flange check valve;

3. The valve disc closes quickly, and the water hammer pressure is small;

4. Horizontal pipeline or vertical pipeline can be used, easy to install;

5. The flow path is smooth and the fluid resistance is small;

6. Sensitive action and good sealing performance;

7. The disc stroke is short, and the impact force of closing the valve is small;

8. The overall structure is simple and compact, and the shape is beautiful;

9. Long service life and high reliability.