Causes and countermeasures of air leakage of pneumatic butterfly valve
During the operation of pneumatic butterfly valve, the pneumatic butterfly valve may show air leakage due to the influence of climatic conditions, line conditions (especially small radius curve), its own quality and other comprehensive factors. Cause analysis: air leakage of pneumatic butterfly 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: refer to the relevant technical requirements of Nanjing Metro, if the pneumatic butterfly 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 butterfly valve for maintenance.