How to identify central air conditioning refrigeration oil

Check oil quality indicators:
Viscosity stability: High-quality refrigeration oil can maintain stable viscosity within the temperature and pressure range of central air conditioning operation. It can be detected by viscosity testing instruments. If the viscosity deviates from the product specifications by more than ±15%, it usually means that the oil quality may be poor, which will affect the lubrication and sealing effects.
Flash point: The flash point is the lowest temperature at which the oil vapor and air mixed with the refrigeration oil can flash when exposed to an open flame after being heated under specific conditions. Generally speaking, the higher the flash point, the better the safety and stability of the refrigeration oil. The flash point of high-quality refrigeration oil is usually 20℃-30℃ higher than the maximum operating temperature of the system.
Pour point: The pour point is the highest temperature at which the refrigeration oil stops flowing under specified conditions, reflecting the fluidity of the refrigeration oil at low temperatures. Good refrigeration oil has a low pour point and can maintain good fluidity when the central air conditioner is running at low temperatures. It should generally be 10℃-15℃ lower than the minimum operating temperature of the system.