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.

Product Performance of York Refrigeration Oil

By Qishanr Lubricants August 1st, 2025 108 views

Core Indicators
1. Precisely matched viscosity: Offering products with viscosity ranging from ISO 32 to ISO 320.
a. K oil has a viscosity index of 130, with a viscosity of approximately 100 cSt at 40℃, which meets the high-temperature and high-pressure requirements of centrifugal compressors.
b. L oil belongs to the ISO 100 viscosity grade, with a 100℃ kinematic viscosity of 14.66 cSt, suitable for screw compressors.

2. Strong temperature adaptability:
a. Excellent low-temperature fluidity, K oil has a pour point as low as -57℃, ensuring smooth oil return in the evaporator at low temperatures.
b. Good high-temperature stability, K oil has a flash point of 230℃, maintaining stability under high-temperature exhaust of the compressor.

3. Strict quality control:
a. Moisture content is strictly controlled below 50 ppm (such as L oil), preventing reaction with refrigerants and corrosion of metals.
b. Typical acid value is ≤ 0.01 mgKOH/g, after hydrogenation process for impurity removal, extending equipment lifespan.

Composition and Formula
1. Mainly based on polyol esters (POE): The L/K/S series use the fourth-generation synthetic POE base oil, which is highly compatible with HFC refrigerants (such as R134a, R410A, etc.), has good miscibility, and strong thermal oxidation stability.
a. K oil has an oxidation induction period of over 200 minutes at 200℃.

2. Special modification and optimization:
a. K oil introduces pentaerythritol ester monomers to enhance hydrolysis stability.
b. L oil uses a blend of diesters and polyol esters to increase oil film thickness while maintaining a low pour point.

3. Additive system synergy:
(1) Anti-wear, dispersion, and oxidation synergy:
a. K oil is combined with ZDDP and borate compound agents for anti-wear.
b. S oil uses butadiene dicarboximide dispersant to control sludge.
c. L oil uses hindered phenols and amine compounds for oxidation.

(2) Customized formula for special scenarios:
a. K oil is modified with silane coupling agent to reduce hygroscopicity.
b. S oil is added with polydimethylsiloxane defoamer to improve anti-foaming performance.

To learn more about York refrigeration oil.