Thread Content
I talked about gate valves a few days ago; today, I’ll take some time to discuss ball valves. As the name implies, a ball valve has a spherical valve core inside. It is divided into floating ball valves and fixed ball valves. Fixed ball valves are used in oil depots, while lift rod-type force-sealing ball valves may be employed at certain connections. External leakage: The reasons for leakage in the valve body and the valve cover are the same; leakage can occur in the valve stem. Ball valves with a lift rod type of forced sealing require packing, while fixed-ball valves use angular motion for operation and do not need packing. Internal leakage: Ball valves also achieve sealing by rotating their sealing surfaces to fit tightly against the valve seat; during rotation, friction occurs between the sealing surface and the valve seat, and frequent opening and closing can lead to the failure of this sealing mechanism. When it is about to start operating or is nearly fully closed, the local scouring of the sealing surface by high-speed media can also lead to failure of the seal. It features a floating valve seat design. The greater the pressure, the tighter the seal surface is pressed against the valve seat, resulting in a better sealing effect. Conversely, the lower the pressure, the less tightly the sealing surface can fit against the valve seat, which leads to leakage. The process by which a lift-type force-sealing ball valve achieves forced sealing is a pendulum-like movement with the lower pivot as a fulcrum. Over time, impurities accumulate between the lower pivot and the ball, resulting in a failure of the sealing mechanism. Leakage hazards: Gate valves and ball valves are used for controlling the loading and unloading of liquids, and their leakage hazards are the same. My experience is limited; feel free to add more!