Large-diameter forged steel ball valves are a type of forged steel valve, widely used in various fluid pipeline systems due to their excellent sealing performance and long service life. Large-diameter forged steel ball valves typically have a larger diameter, generally greater than DN100, meeting the fluid control requirements of large pipeline systems.
Features of Large-Diameter Forged Steel Ball Valves:
1. Employs a resilient movable metal valve seat structure with preloaded cylindrical or wave springs. The reasonable sealing preload design ensures flexible opening and closing, effectively guaranteeing sealing reliability.
2. Can be designed to adapt to media such as dust and slurry, improving the ball valve's wear resistance and high-temperature resistance.
3. Utilizes a specially structured valve stem that not only prevents leakage at the filling point but also prevents the valve stem from detaching.
4. Features fireproof and anti-static properties.
5. This type of ball valve should be used according to the specified flow direction.
Main Functions of Large-Diameter Forged Steel Ball Valves:
1. When the medium stagnating in the valve cavity experiences abnormal pressure rise due to temperature changes, the medium pressure pushes the valve seat away from the ball, achieving automatic pressure relief. After pressure relief, the valve seat automatically resets.
2. In addition to general sealing, the valve seat has a specially designed sealing structure that provides emergency protection against leakage caused by seal damage. 3. When a fire or abnormal temperature causes the valve seat seal to burn or soften, the valve operation remains reliable. Simultaneously, the valve seat and ball form a metal-to-metal seal, achieving a temporary seal and preventing further fire spread, complying with AP16FA regulations.
4. Unscrewing the drain device allows for checking for valve seat leaks and also allows for the discharge of any residue in the cavity, reducing unilateral contamination of the valve by the medium. When the valve is fully open or fully closed during operation, the valve stem packing gland can be replaced.
5. The valve stem seal uses a double seal of PTFE packing and O-rings, making it particularly suitable for gaseous media. The moving parts of the valve stem use high-quality SF self-lubricating bearings, resulting in a lower coefficient of friction and reduced operating torque.