Castrol Aircol SR 68, 208L

Castrol Aircol SR 68 is a premium synthetic rotary compressor lubricant based on polyalphaolefin (PAO) technology and formulated for oil-flooded rotary screw compressors. With an ISO VG 68 viscosity grade, the product is particularly suitable for compressors operating under severe conditions, including extreme climates, harsh environments and applications with very high air discharge temperatures above 100°C. Its excellent oxidation stability, anti-wear performance, low deposit-forming tendency and effective water separation help provide long lubricant and equipment life while supporting reliable compressor operation.

Applications:

Castrol Aircol SR 68 is designed for use in oil-flooded rotary screw air compressors operating under extreme climatic conditions, harsh environments and severe operating conditions where air discharge temperatures may exceed 100°C. The lubricant is also suitable for compressor units operating under normal conditions with maximum air discharge temperatures of up to 100°C, as defined by ISO 6743-3:2003. Under normal operating conditions, Aircol SR products can provide extended oil drain intervals of up to 8,000 hours, depending on the operating environment and equipment conditions.

Product advantages and benefits:

• Extended oil service life: provides typical oil drain intervals of up to 8,000 hours in most systems, depending on the operating environment.
• Excellent high-temperature performance: suitable for severe compressor applications where air discharge temperatures exceed 100°C.
• Very low deposit-forming tendency: helps keep compressor systems cleaner and extends the service life of filters and separators.
• Outstanding oxidation stability: helps resist lubricant degradation and supports long oil service life, even under demanding operating conditions.
• Excellent anti-wear performance: protects compressor components against wear and contributes to extended equipment life.
• Ester-free formulation: eliminates the formation of corrosive acids associated with ester-based formulations, contributing to longer equipment life.
• Excellent water separation: allows condensation to separate readily from the lubricant, minimising the risk of emulsions that could block the oil separator element.
• PAO-based technology: provides good compatibility with seals and mineral oil-based lubricants, facilitating changeover to Aircol SR.
• Excellent low-temperature fluidity: a typical pour point of -54°C supports reliable lubricant circulation under very cold operating conditions.
• High viscosity index: a viscosity index of 142 helps maintain suitable lubricant viscosity over a wide temperature range.

Classification according to DIN and ISO standards:

• ISO VG – 68
• DIN 51506 – VDL
• ISO 6743-3 – DAG, DAH and DAJ for rotary air compressors

Requirements and manufacturer references:

• Atlas Copco – meets requirements for an 8,000-hour oil drain interval
• Kaeser – meets requirements

Seal and lubricant compatibility:
Castrol Aircol SR 68 is fully compatible with nitrile, silicone, polyurethane and fluoropolymer sealing materials typically used in compressor units. The product is not compatible with styrene-butadiene rubber (SBR) or ethylene propylene (EPDM) seals. Its PAO-based formulation also provides good compatibility with mineral oil-based lubricants, allowing changeover to Aircol SR without the compatibility issues typically associated with less compatible synthetic base fluids.

Technical data – Castrol Aircol SR 68:

Performance under severe operating conditions:
Castrol Aircol SR 68 has been developed for demanding rotary screw compressor applications where high discharge temperatures and severe environmental conditions place increased stress on the lubricant. Its strong resistance to oxidation and very low tendency to form deposits help maintain cleaner compressor internals, while its anti-wear properties support reliable protection of mechanical components.

Extended oil drain intervals:
Under normal compressor operating conditions, Aircol SR lubricants can provide extended oil drain intervals of up to 8,000 hours. Actual lubricant service life depends on the operating environment, compressor design, operating temperature and equipment condition. Oil condition and the compressor manufacturer's maintenance recommendations should therefore always be considered when establishing the appropriate drain interval.

Water separation and system cleanliness:
Excellent water separation characteristics allow condensation to readily separate from Castrol Aircol SR 68. This helps minimise the formation of stable oil-water emulsions that could interfere with the performance of the oil separator element. Combined with the lubricant's very low deposit-forming tendency, this contributes to longer filter and separator service life and supports cleaner compressor operation.

Storage and handling:
Castrol Aircol SR 68 should be stored in its original, tightly closed container and protected against water, moisture and contamination. Appropriate safe handling, storage and disposal procedures should be followed in accordance with the current Safety Data Sheet. Before use, the lubricant should always be checked for suitability with the compressor manufacturer's requirements, operating conditions and sealing materials used in the system.

Castrol Aircol SR 68 is a premium synthetic PAO ISO VG 68 compressor oil for rotary screw compressors operating under demanding conditions. Excellent oxidation stability, anti-wear protection, low deposit formation and effective water separation support long lubricant and equipment life. The product is classified as DIN 51506 VDL and ISO 6743-3 DAG, DAH and DAJ.