Sealing structure of electric metal sealed ball valves
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2014-10-07
Electric metal sealed ball valves are mainly divided into two types of sealing structures, namely unidirectional sealing and bidirectional sealing. Unidirectional sealing can only be done in the specified direction, which is the sealing direction indicated by the ball valve. Bi-directional sealing can seal in both directions, and the structural forms of electric hard sealed ball valves are divided into floating ball and fixed ball
Electric metal sealed ball valves are mainly divided into two types of sealing structures, namely unidirectional sealing and bidirectional sealing. Unidirectional sealing can only be done in the specified direction, which is the sealing direction indicated by the ball valve. Bidirectional sealing can seal in both directions. The structural forms of electric hard sealed ball valves are divided into floating ball and fixed ball, and the connection forms are flange connection, welding connection, and threaded connection. The electric actuator is equipped with a built-in servo system, without the need for an additional servo amplifier. By inputting a 4-20mA signal and a 220VAC/380V power supply, the operation can be controlled.
Electric hard sealed ball valves have the advantages of simple connection, compact structure, small size, light weight, low resistance, and stable and reliable operation. They are mainly used in situations where two positions are cut off and adjusted. The connection between the ball valve and the actuator adopts a direct connection method. Electric metal sealed ball valves are mainly suitable for working conditions with temperatures above 250 degrees Celsius.
Electric metal sealed ball valves have been widely used in industries such as petroleum, chemical, metallurgy, and urban central heating. However, ball valves made of PTFE polymer material used for sealing cannot be used in conditions where the temperature exceeds 280 ℃ or the conveying medium is in the form of small particles. Hard sealed ball valves with metal materials as sealing pairs may encounter various situations due to different structures when rotating the ball. As for the metal elastic valve seat sealing structure, there is no gap between the elastic valve seat and the ball, so its friction force is very high.
The metal floating valve seat sealing structure makes it difficult to seal between the floating valve seat and the valve body. The combination ball supported open sealing structure, due to its numerous components and complex structure, increases the difficulty of processing and manufacturing costs, especially for small diameter hard sealed ball valves. This structure is obviously not suitable. After repeated analysis and testing, and with the help of CAD aided design, the Q47H cam eccentric single seat fixed hard sealing ball valve has been successfully developed.
