Structure Of Fixed Ball Valve
The sealing is good, but the load of the sphere bearing the working medium is all passed to the outlet seal ring, so it is necessary to consider whether the sealing ring material can withstand the working load of the spherical medium, and the sphere may shift when it is hit by a higher pressure.
This structure is generally used in medium and low voltage ball valves. The sphere of the ball valve is fixed and does not produce movement after being pressed. Fixed ball valves are equipped with floating seat, after the media pressure, the seat is moved, so that the seal ring pressed on the sphere to ensure sealing.
Bearings are usually fitted with the upper and lower axes of the sphere, with small operating torque and are suitable for high pressure and large caliber valves. In order to reduce the operating torque of the ball valve and increase the reliability of the seal, and the emergence of oil seal ball valve, not only in the sealing surface pressure special lubricating oil, in order to form a layer of oil film, that is, enhance the sealing, but also reduce the operating torque, more suitable for high-pressure large-caliber ball valve.