Compressor oil lubricates rotor / piston / cylinder in air, gas and vacuum compressors. Three families: rotary screw (Atlas Copco, IR, ELGI, Kaeser industrial workhorse), reciprocating piston (older plant air), and process gas compressor (refinery / petrochemical specialty). This guide gives the recommended ISO VG 46 PAO + ester rotary screw BOM, reciprocating semi-synthetic alternative, and Indian aftermarket positioning.
| Component | Function | % (m/m) | Indian Supplier |
|---|---|---|---|
| PAO 4 cSt base oil | Primary synthetic base, thermal stable | 35.0% | INEOS Durasyn / ExxonMobil SpectraSyn |
| PAO 6 cSt base oil | Heavy PAO for KV40 target | 45.0% | INEOS Durasyn / SpectraSyn |
| Polyol ester (PE-trioleate) | Solvency — prevents screw varnish | 10.0% | Croda Priolube / specialty ester |
| R&O additive package (Afton HiTEC 4951) | Rust + oxidation + AW combined | 1.5% | Afton / Lubrizol / Lubechem LC-RO-COMP |
| Methylene-bis-DTBP phenolic AO | Low-volatility primary AO | 0.5% | Albemarle Ethanox 4710 |
| Alkylated DPA aminic AO | High-temp secondary AO | 0.4% | LANXESS Naugalube 438L |
| ASA + thiadiazole CI | Ferrous + yellow-metal | 0.4% | King K-Corr + Vanderbilt 887 |
| Foam inhibitor (silicone + polyacrylate) | Foam control oil-flooded screw | 100 ppm | Dow Corning + polyacrylate blend |
| Demulsifier (polyalkylene oxide) | Water separation in air system | 0.05% | Specialty demulsifier suppliers |
| PMA PPD | Cold-start pour point | 0.2% | Lubrizol Sandura / Evonik Viscoplex 1 |
| Group III diluent | KV / VI fine-tune | 6.94% | Group III |
| TOTAL | 100.0% | — | |
Process: blend PAO + ester at 60 °C; charge R&O package + AO + CI; PPD and foam inhibitor last. QC: KV40 46 cSt ±5%, VI ≥130, pour <-40 °C, RPVOT D2272 >2,000 min, D943 TOST >5,000 hr, foam D892 Seq I <25/0/0, demulsibility D1401 ≤30/40/0 in 40 min, copper strip 1B. Ex-works cost ₹240-340 / L at 5 MT batch. OEM compat: Atlas Copco Roto-Z, IR Ultra Coolant equivalent positioning.
Compressor oil lubricates rotors / pistons / cylinders. Three families: (1) Rotary screw (Atlas Copco, Ingersoll Rand, Kaeser, ELGI, Chicago Pneumatic) — workhorse industrial air compressor, oil-flooded, PAO synthetic ISO VG 46/68, 8,000 hr drain. (2) Reciprocating piston — older plant air, mineral or semi-syn ISO VG 100/150, 1,000-2,000 hr drain. (3) Process gas — specialty matched to gas (CO2, NH3, hydrocarbon, oxygen).
Gas-compatibility critical. Each family has different chemistry per application.
ISO VG 46 rotary screw BOM (%): PAO 4 cSt 35%, PAO 6 cSt 45%, polyol ester 10%, R&O additive package 1.5%, methylene-bis-DTBP phenolic AO 0.5%, aminic AO 0.4%, ASA + thiadiazole CI 0.4%, foam inhibitor 100 ppm, demulsifier 0.05%, PMA PPD 0.2%, balance Group III diluent.
QC: KV40 46 cSt, VI 130+, RPVOT >2,000 min, D943 TOST >5,000 hr, foam D892 <25/0/0, demulsibility D1401 pass. Ex-works ₹240-340/L.
Rotary screw operates with oil at 90-110 °C continuous, brief excursions to 130 °C. Mineral oil oxidises rapidly; varnish forms; drain interval limited to ~2,000 hr. PAO has 3-4x oxidation life of Group I, with low pour and high VI. Polyol ester adds: (1) thermal stability, (2) inherent solvency that prevents varnish on screw rotor, (3) seal compat for NBR / HNBR.
80% PAO + 10-15% ester is standard premium screw compressor oil. Cheap alternatives use Group III only — acceptable but shorter drain.
Reciprocating compressor uses splash or pressure-fed lubrication of piston rings, crosshead, bearings. Higher viscosity (ISO VG 100 / 150) for piston ring sealing. BOM: Group II 220N + 600N 90%, R&O + AW 4%, phenolic AO 0.5%, aminic AO 0.3%, ASA CI 0.5%, PMA VII 4%, PPD 0.3%, foam inhibitor 100 ppm.
Ex-works ₹130-200/L. Reciprocating handles cooler oil temperature (60-90 °C) than rotary screw — less demanding oxidation life. Drain 1,000-2,000 hr typical.
India compressor oil — ~120-180 ML/year. OEM channel: Atlas Copco India (Roto-Inject), Ingersoll Rand India (Ultra Coolant), ELGI, Kaeser, Chicago Pneumatic. Aftermarket: IOCL Servo, BPCL Mak, HPCL HP, Castrol Aircol, Shell Corena, Mobil Rarus.
₹240-580 / L OEM-licensed, ₹160-280 / L aftermarket. Lubechem custom (LC-COMP-VG46-PAO) ex-works ₹240-340/L for rotary screw PAO; ₹130-200/L for reciprocating.
Rotary screw drain driven by oxidation life. Mineral / Group I: 2,000-4,000 hr. Group II: 4,000-6,000 hr. Group III: 6,000-8,000 hr. PAO + ester premium: 8,000-12,000 hr (some OEM 16,000 hr). Drain triggered by: TAN >2.0, varnish on sight glass, viscosity rise >15%, particle count >ISO 18/16/13.
Aftermarket oil analysis (Indian Oil Lab, IIP Dehradun, AES Lab Mumbai) ₹800-2,500 per sample. Indian factory maintenance increasingly uses oil analysis to extend drain to condition-based rather than calendar-time.
Share your compressor type (rotary screw / reciprocating / vacuum), OEM, target drain life and volume. We respond within one business day with the BOM and ex-works cost.