Causes and Countermeasures of Air Leakage in Pneumatic Ball Valves
During the application of pneumatic ball valve, due to the influence of climate conditions, line conditions (especially small radius curve), the quality of pneumatic ball valve itself and other comprehensive factors, the pneumatic ball valve may show air leakage. Cause analysis: air leakage of pneumatic ball valve mainly occurs between the upper cover and the capsule. After 6~8 years of train operation, the data performance gradually ages, and the upper cover and capsule sealing part will also experience permanent deformation. When suddenly receiving a large transverse impact, the upper cover and capsule sealing part will show mismatch and air leakage will occur. Especially in winter when the temperature drops, the data performance becomes worse, and it is easier to show air leakage. Disposal method: according to the relevant technical requirements of Nanjing Metro, if the pneumatic ball valve shows slight air leakage during vehicle operation, the main air duct pressure drop does not exceed 0.15 bar within 5 minutes after the vehicle air tightness test, it can continue to be used. If the leakage is exceeded, stop changing the pneumatic ball valve for maintenance.