Causes of internal leakage of the ball valve during operation

① The most common reason is that the operation manager does not maintain the valve in consideration of the relatively expensive maintenance costs, or lacks scientific valve management and maintenance methods and does not perform preventive maintenance on the valve, resulting in early failure of the equipment;
② Internal leakage caused by improper operation or failure to follow the maintenance procedures;
③ During normal operation, construction residues scratch the sealing surface, causing internal leakage;
④ Improper pigging causes damage to the sealing surface and causes internal leakage;
⑤ Long-term non-maintenance or inactive valves will cause the valve seat and ball to lock up, causing seal damage and internal leakage when the valve is switched on and off;
⑥ The valve switch is not in place to cause internal leakage. Regardless of the open or closed position of any ball valve, the general inclination of 2° to 3° may cause leakage [2];
⑦ Many large-diameter ball valves have stem stoppers. If they are used for a long time, rust, dust, paint and other debris will accumulate between the valve stem and stem stoppers due to corrosion. Unable to rotate in place and cause leakage – If the valve is buried, the lengthened valve stem will produce and drop more rust and impurities to prevent the valve ball from rotating in place, causing the valve to leak,
⑧ The general actuator also has a limited position. If it is rusted for a long time, the grease hardens or the limit bolt is loose, the limit will be inaccurate and cause internal leakage;
⑨ The valve position of the electric actuator is set to the front, and it is not closed properly, resulting in internal leakage;
⑩ Lack of periodic maintenance and maintenance will cause the sealing grease to dry and harden, and the dried sealing grease will accumulate behind the elastic valve seat, hindering the movement of the valve seat and causing the seal to fail.