Butterfly valve is a common industrial pipeline equipment, which is widely used in fluid control in various fields. The sealing performance of the butterfly valve has always been controversial. Some people think that the butterfly valve is a one-way seal, while others think that the butterfly valve is a two-way seal. So, is the butterfly valve a two-way seal or a one-way seal?
Butterfly valve sealing principle
The sealing principle of the butterfly valve is to form a seal through the sealing material built into the valve body and the edge of the valve disc connected to the valve stem. When the disc is rotated to the closed position, the edge of the disc will be in full contact with the seat surface to form a one-way seal. At the same time, the design of the sealing material and the edge of the disc can also make the butterfly valve realize two-way sealing.
Classification of butterfly valves and corresponding applicable working conditions
According to different structures and usage occasions, butterfly valves can be divided into jacketed butterfly valves, triple eccentric butterfly valves, soft-sealed butterfly valves, metal-sealed butterfly valves, etc. These butterfly valve types can exert good control effect and sealing performance in different industries and working conditions.
Jacketed butterfly valve is a relatively common type of butterfly valve in China. Its advantages lie in its simple structure and convenient installation and maintenance. However, due to the short service life of its sealing material, it cannot be replaced, so it is not suitable for high temperature, high pressure and corrosive medium occasions.
Triple eccentric butterfly valve, also known as eccentric hemispherical valve, adopts different materials and structural designs, can be used in harsh environments such as high temperature, high pressure, and strong corrosion, and has excellent bidirectional sealing performance. It is an ideal choice for medium and high pressure pipeline flow regulation.
The soft seal butterfly valve is suitable for most general industrial applications, and the sealing material can be selected and replaced according to different media and working conditions. This type of butterfly valve is simple in design and relatively low in price, but its sealing performance gradually decreases with the increase of use time.
Metal seal butterfly valves are mainly used in special environments such as high temperature, high pressure, and strong corrosion. This type of butterfly valve adopts a metal sealing structure, and the sealing performance is stable and reliable, but the price is relatively high.
In short, the sealing performance of butterfly valve is not a single mode, but a comprehensive result affected by many factors. In actual operation, according to different working conditions and application requirements, we can select and optimize the type, material and structure of butterfly valves to achieve the best control effect and sealing performance.