Refrigerant Classification Knowledge

According to GB/T 7778-2017, the safety of refrigerants is divided into 8 categories: A1, A2L, A2, A3, B1, B2L, B2, B3, among which A1 is the safest and B3 is the most dangerous.
The safety levels of common refrigerants are as follows:
Class A1: R11, R12, R13, R113, R114, R115, R116, R22, R124, R23, R125, R134a, R236fa, R218, RC318, R401a, R401b, R402a, R402b, R403a, R403b, R404a, R407a, R407b, R407c, R407d, R408a, R409a, R410a, R417a, R422d, R500, R501, R502, R507a, R410a 508a, R508b, R509a, R513a, R744
Class A2: R142b, R152a, R406a, R411a, R411b, R412a, R413a, R415b, R418a, R419a, R512a
A2L class: R143a, R32, R1234yf, R1234ze (E)
Class A3: R290, R600, R600a, R601a, R1270, RE170, R510a, R511a
Class B1: R123, R245fa
B2L class: R717
According to the evaporation temperature ts of refrigerants under standard atmospheric pressure (100kPa), they can be divided into high-temperature refrigerants, medium temperature refrigerants, and low-temperature refrigerants.
Low pressure and high temperature refrigerant: evaporation temperature above 0 ℃, condensation pressure below 29.41995 × 104Pa. This type of refrigerant is suitable for centrifugal refrigeration compressors in air conditioning systems.
Medium pressure medium temperature refrigerant: Evaporation temperature -50~0 ℃, condensation pressure (196.113~29.41995) × 104Pa. This type of refrigerant is generally used in piston refrigeration systems with ordinary single stage compression and double stage compression.
High pressure and low temperature refrigerant: High pressure and low temperature refrigerant: Evaporation temperature below -50 ℃, condensation pressure above 196.133 × 104Pa. This type of refrigerant is suitable for the low-temperature part of cascade refrigeration devices or low-temperature devices below -70 ℃.