The difference and application of double eccentric and triple eccentric butterfly valves

Double eccentric butterfly valves and triple eccentric butterfly valves are widely used valve types in the industrial field. They play a vital role in fluid control and are used in various industries such as petroleum, chemical, food processing, and water treatment. Knowing the difference between them is critical to the correct selection and application of the proper valve.

Structural design difference: The design of the double eccentric butterfly valve includes two eccentric shafts, one of which is located at the center of the butterfly plate and the other is located at the periphery of the butterfly plate. This structure enables the butterfly plate to reduce friction when opening and closing, thereby reducing the operating force. In contrast, the design of the triple eccentric butterfly valve adds a third eccentric shaft to the butterfly plate, so that the butterfly plate can be completely separated from the seat ring when it is closed, thereby reducing the sealing pressure and improving the sealing performance.

Difference in working principle: The double eccentric butterfly valve controls the flow of fluid by rotating the butterfly plate. When the butterfly plate is fully opened, a large channel is formed between the butterfly plate and the seat ring, so that the fluid can pass through smoothly. On the contrary, when the butterfly plate is closed, the channel will be completely closed, preventing the passage of fluid.

The working principle of the triple eccentric butterfly valve is similar to that of the double eccentric butterfly valve, but it adjusts the position of the butterfly plate through the eccentric shaft of the butterfly plate so that it can completely disengage from the seat ring when it is closed. This design can reduce the wear of the sealing surface, prolong the service life of the valve, and improve the performance of sealing and high pressure resistance.Differences in application scenarios: Double eccentric butterfly valves are usually used in medium and low pressure and general fluid control applications. Its simple structure and flexible operation are suitable for occasions that require frequent opening and closing. For example, the valve is often used in water supply and drainage systems, waste water treatment and air conditioning systems, etc.

In contrast, the triple eccentric butterfly valve is suitable for higher pressure and more severe working conditions. Due to its optimized sealing performance and high pressure resistance, it is often used in the fields of petroleum, chemical industry, natural gas and thermal power generation. In addition, the triple eccentric butterfly valve is also suitable for the control of corrosive media and high temperature media.

Conclusion: There are obvious differences between double eccentric butterfly valve and triple eccentric butterfly valve in structural design, working principle and application scenarios. Double eccentric butterfly valves are suitable for medium and low pressure and general fluid control, while triple eccentric butterfly valves are suitable for higher pressure and more severe service conditions. Proper selection and application of appropriate valves is critical to ensure proper operation and safety of the system. Therefore, in practical applications, it is a very important decision to choose the most suitable valve type according to the specific needs and working conditions.