Floating ball
Pneumatic ball valve ball is floating in the medium pressure, the ball can produce a certain displacement and pressure in the export side of the sealing surface, to ensure that the export side seal.
Floating gas dynamic ball valve structure is simple, good sealing, but the ball under the load of working medium to pass all the export ring, so to consider sealing ring material can withstand the work load of the media sphere. This structure is widely used in medium and low pressure ball valve.
Fixed ball
Pneumatic ball valve of the ball is fixed, the pressure does not produce movement. Fixed ball valve with a floating seat, by the media pressure, the valve seat to move, so that the sealing ring on the ball, in order to ensure that the seal. Usually with the ball in the upper and lower shaft with bearings, operating torque, suitable for high pressure and large diameter of the valve.
In order to reduce the aerodynamic valve operating torque and increase the reliability of the seal, valve seal, both in the sealing surface pressure injection of a special lubricant, to form a layer of film that enhances the sealing, and reduce operating torque, more suitable for large-diameter high-pressure ball valve.
elastic ball
Pneumatic ball valve of the ball is elastic. Sphere and valve seat ring are made of metal materials, sealing pressure is very large, depending on the pressure of the medium itself has reached less than the requirements of the seal must be applied. This valve is suitable for high temperature and high pressure medium.
An elastic ball is provided with an elastic groove at the lower end of the inner wall of the ball. When the channel is closed, the ball is opened and the valve seat is pressed to seal by the wedge head of the valve rod. Before turning the ball to loosen the wedge head, the ball will be restored to the original shape, so that a small gap between the ball and the seat, you can reduce the friction of the sealing surface and operating torque.
Pneumatic valve position according to their channels can be divided into straight through three and right angle type. After two kinds of ball valve for the distribution of media and change the flow of media.
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