Natural gas ball valve gate leakage causes and treatment methods
The reason of ball valve gate leakage 1) During the construction of the cause of the valve gate leakage: (1) valve door overall damage caused by improper transportation and hoisting causing the valve gate leakage; (2) the factory, after the water pressure not to dry processing and anticorrosive processing of gate valve, sealing surface rust formation of leakage; (3) the construction site protection does not reach the designated position, not with blind flange on both ends of the valve gate, rain, sand and other impurities in the valve seat, cause leakage; 4. When installation, not to inject grease valve seat, caused by impurities into the valve seat back, or burn when welding the cause of leakage; 5 valves are not in the fully open position for installation, sphere damage, when welding, if the valve is not in the fully open position, welding spatter material will cause damage to sphere, when accompanied by welding spatter material sphere when the switch will cause the valve seat further damage, resulting in leakage; 6 pieces construction such as welding slag sealing surface scratch; 7 ex-factory time limit or install a leakage caused by inaccurate, if the valve stem drive units or other accessories with the assembly of angular misalignment, goalkeeper valve leakage. 2) Running period of the cause of the valve gate leakage: (1) the most common reason is operating managers to consider more expensive maintenance on the valve gate is not maintained, or the lack of scientific valve gate management and maintenance methods of the valve gate no preventive maintenance, equipment malfunction in advance; (2) improper operation or not carried out in accordance with the maintenance program maintenance cause of leakage; (3) in normal operation, construction relic scratch sealing surface, the cause of leakage; (4) improper pigging sealing surface damage cause of leakage; Valve gate 5. Long-term maintenance, or activity, cause the valve seat and ball lock, the switch valve door seal damage form of leakage; 6. Cause of leakage valve door switch does not reach the designated position, any ball valve door, no matter, tilt commonly 2 & deg; ~ 3度; It may cause leakage; 7 many large-diameter ball valve door have a valve rod retaining block, if long time, due to reasons such as rust in the valve stem and valve stem stop between blocks will accumulate rust, dirt, paint and other sundry, the clutter valve door does not spin in place due to leakage & ndash; — If the valve door is buried, lengthen the valve rod and falling more rust and impurities hinder valve ball spin in place, cause the valve gate leakage, was generally actuator is limited, if long-term rust, grease hardening or limit bolt looseness will make limit is inaccurate and cause of leakage; Pet-name ruby electric actuator valve setting, not the cause of leakage in place; and Attending a lack of regular maintenance and maintenance, sealing grease dry and harden, dry sealing grease accumulation after the elasticity of the valve seat, the block valve motion, resulting in seal failure. Gas ball valve gate leakage judgment method is commonly used in the gas pipeline ball valve door fixed axis, its general check method is: door turn to fully open or close the valve, through the valve body pollutant discharging mouth emissions check for leaks. If you can clean, you prove good seal. If there is always pressure discharge, it can be thought of as the valve gate leakage, then should make the corresponding processing the valve gate. Gas ball valve gate leakage handler (1) the first check valve door limit, whether by adjusting the spacing can solve leakage of valve gate. (2) by injecting a certain amount of grease to see whether could stop leakage, injection speed must be slow at this moment, at the same time observe the change in the grease gun export pressure gauge pointer to the internal leakage of the valve gate. (3) if you can't stop leakage, it is possible that early sealing grease injection harden or sealing surface damage cause of leakage. Advice when door cleaning fluid injection valve, the valve sealing surface of the door and the valve seat for cleaning. Generally at least for half an hour, if necessary can soak for a few hours or even days, dissolve to be cured and then take the next step. In this process a few times can be the best valve door switch activity. (4) to inject grease, intermittent valves open and close the door, the impurities discharge valve cavity and seal face after. (5) in a fitted for inspection, if there is still a leak, sealing grease injection should be strengthen level, at the same time open the vent valve cavity, so that we can produce the large pressure difference, helps to seal, under normal circumstances, the level by injecting strengthen internal leakage sealing grease can be eliminated. 6. If there is still leakage, the valve door for repair or replacement.