a) CategoryⅠ: Railway vehicles with a running speed of less than 200km/h, and air springs with all diaphragm structures; b) Category Ⅱ: Railway vehicles with a running speed of 200km/h and above, and air springs with large curved diaphragm structures; c) Category Ⅲ: air springs with a running speed of 200km/h and above for railway vehicles and diaphragm with small curved. In special cases, the type of air spring shall be determined by negotiation between the supplier and the buyer.
The air spring should be able to withstand the user's requirements for the environmental conditions of the operating line, such as wind, sand, snow, occasional salt spray, acid rain, sandstorms, etc., as well as the minimum curve radius and operating speed requirements.