концентрические клапан-бабочка: простая конструкция

The concentric butterfly valve is a straightforward and widely used control valve, primarily employed in low-pressure piping systems for the control of medium flow and shut-off. Its main characteristic is the use of a disc-shaped valve disc (also known as the butterfly plate) as the closing element, which rotates around the valve shaft to open and close the valve. This type of butterfly valve is suitable for a variety of fluids, including air, water, steam, various corrosive media, sludge, oils, liquid metals, and radioactive media. Due to its excellent cutting and throttling functions, the concentric butterfly valve plays a significant role in piping systems.

Structural Features

The design of the concentric butterfly valve is very simple, typically consisting of the valve body, valve seat, valve shaft, and butterfly plate. The principle of opening and closing is through the rotation of the butterfly plate to control the flow of the medium. The butterfly plate rotates approximately 90° within the valve body along its axis to achieve full open or full close, and precise flow adjustment can also be made as needed. Compared to other types of valves, the concentric butterfly valve has the following significant advantages.

Compact structure: Due to its simple design and small space occupation, the butterfly valve is particularly suitable for installation in spaces with limited space.
Light weight and easy installation: The butterfly valve consumes less material and is easy to install and operate, making it particularly suitable for large-diameter valve applications.
Low operating torque: The rotation of the butterfly plate reduces the friction during operation, making it more effortless.

Materials and Sealing Technology

To meet different working conditions, the sealing materials of the concentric butterfly valve are diverse, evolving from early synthetic rubber to polytetrafluoroethylene (PTFE) and metal sealing materials.

1. Synthetic Rubber Sealing

Synthetic rubber was an early choice for butterfly valve sealing materials due to its excellent corrosion resistance, erosion resistance, dimensional stability, and good elasticity. Synthetic rubber is easy to mold, has low costs, and different types of rubber, such as neoprene and nitrile rubber, can be chosen based on specific usage conditions to meet different application needs.

2. Polytetrafluoroethylene (PTFE) Sealing

PTFE has become an ideal sealing material for butterfly valves due to its excellent chemical stability, low coefficient of friction, resistance to aging, and strong dimensional stability. By filling with reinforcing materials, the strength and wear resistance of PTFE are enhanced, overcoming the limitations of synthetic rubber in certain extreme environments, allowing the butterfly valve to maintain good sealing performance and longer service life over a wider range of temperatures and pressures.

3. Metal Sealing

To adapt to extreme conditions such as high temperature, high pressure, and strong corrosion, metal-sealed butterfly valves have developed rapidly. Modern metal-sealed butterfly valves use high-strength alloy materials, such as stainless steel and titanium alloys, which have excellent resistance to high and low temperatures and erosion. Especially under high-temperature and high-pressure conditions, the sealing and reliability of metal-sealed butterfly valves are significantly superior to non-metallic sealed butterfly valves and are widely used in key working conditions in industries such as power and petrochemicals.

Performance Improvement and Technological Development

The application of concentric butterfly valves continues to expand, especially in the field of large-diameter and high-pressure fluid regulation. The butterfly valve has minimal flow resistance in the fully open state; and when the opening angle is between 15° and 70°, precise flow control can be achieved. Therefore, butterfly valves are widely used in large-diameter pipeline flow regulation fields, such as water supply projects and large-scale heating systems.

Moreover, the motion of the butterfly plate has a wiping effect, giving the butterfly valve an advantage in controlling media with suspended solid particles. Depending on the strength of the sealing elements, butterfly valves can also be used to control powdery and granular media. In recent years, through continuous innovation in materials and structure, the technical level of butterfly valves has reached new heights. For example, butterfly valves with large diameters (9 to 750 mm), high pressure (up to 42.0 MPa), and a wide temperature range (-196 to 606°C) can meet the fluid control needs under extreme conditions.

As the demands on valve performance in process flows increase, concentric butterfly valves are moving towards high-temperature, high-pressure, large-diameter, and multi-function directions. The application of new materials and sealing technologies has made butterfly valves more versatile and longer-lasting. Future butterfly valve products will focus more on reliability, durability, and sealing performance to meet more stringent industrial conditions and energy-saving and environmental protection requirements.

Conclusion

In summary, with its simple design and excellent performance, the concentric butterfly valve has become an indispensable core equipment in industrial fluid control. As material science and sealing technology continue to advance, the concentric butterfly valve is constantly moving towards a more intelligent and multifunctional direction to meet more stringent and diverse working conditions. In the future, it will demonstrate higher reliability and durability in more fields, promoting innovation and development in fluid control technology, and helping industrial systems to operate more efficiently and environmentally friendly.