What type of refrigeration oil should I use for my screw compressor?

Screw compressors typically require POE (Polyol Ester) oils for HFC refrigerants like R134a and R407C, or mineral oils for HCFC systems like R22. The viscosity grade (usually ISO VG 32-68) depends on the compressor manufacturer's specifications. Brands like Bitzer recommend BSE series POE oils, while FUSHENG systems often use mineral oil formulations.

What is the difference between POE and mineral refrigeration oil?

POE (Polyol Ester) oils are synthetic lubricants designed for HFC refrigerants (R134a, R404A, R407C, R410A) and are hygroscopic, requiring careful moisture control. Mineral oils (MO) are petroleum-based, used with CFC and HCFC refrigerants (R22, R502), and are less expensive but incompatible with modern HFC systems. POE oils offer better thermal stability and miscibility with newer refrigerants.

How do I select the right refrigeration oil for a centrifugal chiller?

For centrifugal chillers, select oil based on the OEM specification (e.g., Trane OIL00037, York PureOil S), the refrigerant type (R123 low-pressure or R134a medium-pressure), and the required viscosity grade. Most modern centrifugal chillers use POE oils with ISO VG 32-68. Always verify compatibility with the chiller manufacturer's technical bulletin and ensure the oil meets the required pour point for your operating conditions.

SUNISO GS/GSD Series Refrigeration Oil

By Qishanr Lubricants September 11th, 2025 73 views

Applications

Refrigeration compressors using CFC, HCFC, HFO or natural refrigerants.

The GS/GSD series can be used in any equipment regardless of the compressor type or HCFC evaporation temperature, and can also be used stably with refrigerants such as R22, R717, R290, and R1233zd(E).
The GSD series has enhanced defoaming performance, so it can solve the foaming problem at startup.

Advantages

Provide high efficiency and safety for your compressor.

Its chemical stability extends service life and reduces costs.
Its cleaning function can reduce the residue of deposits that cause compressor valve seat clogging.
Excellent low - temperature performance, no precipitates that block the system oil circuit will be separated out.

Specifications

Certification/Recommendation/Reference
Bitzer, Bristol, Carlyle, Copeland, Daewoo, Daikin, Dorin, Embraco, Fusheng, GEA Bock, GEA Grasso, GMCC, HANBELL, Hasegawa Refrigeration, Mayekawa, McQuay, Hitachi, KOBELCO, Kulthorn Kirby, LG, Mitsubishi Heavy Industries, Panasonic, Sanyo, Samsung, Toshiba Carrier, Tatung, Tecumseh, Thermo King and more.

Typical Data

Analysis	Unit	Method	3GS	4GS	5GS	3GSD	4GSD	5GSD
ISO Viscosity	-	-	32	56	100	32	56	100
Density at 15°C	g/cm³	ASTM D4052	0.909	0.915	0.921	0.910	0.915	0.925
Viscosity at 40°C	mm²/s	ASTM D445	29.5	54.9	94.6	29.5	54.5	96.5
Viscosity at 100°C	mm²/s	ASTM D445	4.3	6.0	7.8	4.4	6.1	8.1
Pour Point	°C	ASTM D97	-40.0	-35.0	-27.5	-40.0	-35.0	-25.0
Flash Point (COC)	°C	ASTM D92	178	188	208	178	182	188