Ball Valve Structure
Good sealing, but spheres work under medium load to export all seals, so consider sealing material can withstand sphere medium work loads, when subjected to high pressure, sphere may be offset. This structure, generally used for medium-pressure ball valves.
Ball valve ball is fixed, the compression does not move. TRUNNION mounted ball valve with floating seats, affected by the media pressure, seat movement, seal pressed in on the ball, to ensure the sealed. Usually in the sphere of the upper and lower shaft with bearings, small operation twist, suitable for high pressure and large diameter valves.
In order to reduce the ball valve operating torque and increased reliability of sealing, there was oil seal ball valve, both at the bet special lubricating oil on the sealing surface, to form a film of oil, which enhances seal and reduces operating torque, more suitable high pressure large diameter ball valves.