Ball valve is closed as the sphere of the health-class butterfly valve. The main function of the ball valve is to cut off and connect the fluid in the pipeline. Ball valve is featured by small fluid resistance, good sealing, fast switching and high reliability.
Ball valve is mainly composed of valve, stem, ball and sealing ring and other components, is a 90 ° switch cut valve, which by means of the handle or drive device in the upper end of the stem exert a certain torque and passed to the ball, it rotated 90 °, The through hole of the sphere is coincident with or perpendicular to the center line of the valve body passageway, and the full opening or full closing action is completed. Ball valve structure commonly used floating ball and fixed ball valve two categories.
Floating ball valve ball freely supported on the ring, under the action of fluid pressure, close contact with the downstream seal, forming the downstream side of single-sided seal. It is suitable for low-pressure, small-caliber applications.
The fixed sphere ball has the upper and lower shafts, fixed in the ball bearing, therefore, the sphere is fixed, but the seal is floating, sanitary diaphragm valve by means of spring and fluid thrust to the ball, resulting in upstream seal. It is applicable to high-pressure, large-caliber occasions.
In the underground facilities, offshore operating platforms and submarine equipment are for direct-welded ball valve. Direct-welded ball valve with high-quality forged parts in the middle part of the valve through the integration of single-layer welding integration, so that the shape of the valve is more similar to the ball, the valve structure is more compact, lighter weight, greater intensity. Single-layer direct welding can also achieve the level of high-precision valve manufacturing, so that between the seat and the ball can be fully sealed. It completely welded without the use of bolted body design to completely eliminate the external leakage, at the same time, the use of such a ball valve structure design, without any maintenance.
Sanitary ball valve is a multi-turn ball valve, which uses the principle of tilt and rotation to eliminate the sealing surface abrasions. When the valve is closed, the ball core is by mechanical force wedge to the sealing seat, without relying on the help of differential pressure can ensure tight seal; when the valve opens, the ball core from the seat, the pipeline along the ball fluid. The core surface of 360 ° through the valve, can eliminate high-speed fluid on the seat of the local erosion. As the valve on and off when there is no friction, so the operation light and reliable.