Oil Free Rotary Screw Air Compressors

37-300kW Fixed Speed Oil Free Air Compressors37-300kW Fixed Speed Oil Free Air Compressors

Looking for a rugged and reliable oil-free air compressor? Ingersoll Rand’s Sierra Oil-Free rotary screw is just the unit for you. With Ingersoll Rand’s unmatched reputation for reliability and performance to count on, oil-free customers can enjoy the peace of mind so difficult to come by given their vital process and application needs.


  • ISO Class 0 Certified
    Ingersoll Rand was the first to deliver ISO Class 0 in both rotary-screw and centrifugal technologies. ISO 8573-1:2010 Class 0 specifies air quality standards for critical manufacturing processes within the food and beverage, pharmaceutical, textile and electronics industries. It is the most stringent class, covering oil contamination in aerosol, vapor and liquid forms. Count on Sierra Oil-Free compressors to deliver pure air, unmatched energy efficiency and peace of mind.
  • Advanced Compression Module Technology
    The two-stage compression module, with oil-free rotary screw technology, is the heart of the Sierra package. It makes the Sierra the toughest machine in the business. Stainless steel is used for critical sealing components, as well as for the high pressure rotor set. Combined with the use of the “ultracoating” process for the rotors and housing bores, this module design offers double protection against wear and the effects of corrosion.
  • Superior Rotor Coating Design
    Decades of oil-free rotary compressor experience have taught us how vital the rotor/housing coating is to initial and lasting compressor performance. As a result, UltraCoat was designed specifically for this oil-free compressor application, with its unmatched adhesion, durability, and temperature resistance properties the key selection criteria. But the real key for the customer is the optimum long term compressor performance, through minimized coating wear and efficiency degradation. In short, this means more compressed air for the operating cost dollar.
  • Ingersoll Rand Packaging
    The Sierra’s packaging features were designed for optimum customer benefit. The 115ºF (46ºC)ambient rating lessens the chance for nuisance shutdowns due to summer heat or dirty coolers. The package air flow materials of construction, stainless steel for cold-side piping, aluminum for the moisture separators, and the non-corrosive compression module components add to the compressor’s operating life and insure the delivery of clean compressed air.
  • Flexibility
    With Sierra, the choice is yours for an air or water-cooled package. Both have been designed for optimum performance. Also, wrapped around the many standard features are a variety of package options, available to meet special application needs. Outdoor modification, low ambient protection, and complete Nema 4 are just a few of the pre-engineered choices.

37-300kW Fixed Speed Oil Free Air Compressors Brochure

37-160kW Variable Speed Drive Oil Free Air Compressors

37-160kW Variable Speed Drive Oil Free Air CompressorsThe Nirvana Oil-Free air compressor, with a matching standard variable speed inverter and HYBRID PERMANENT MAGNETTM MOTOR coupled with a time-proven, oil-free, compression module, represents a stunning advance in compressor technology. The Nirvana Oil-Free rotary compressor provides unparalleled energy efficiency at all speeds and offers superb reliability. There are no motor bearings, pulleys, belts, couplings or motor shaft seals to wear out, leak or need replacing. Nirvana will lower your operating costs with its dynamic efficiency. Nirvana Oil-Free offers truly transcendent technology.


  • ISO Class 0 Certified
    ISO 8573-1 edition 2, 2010 Class 0 100% oil-free air under all operating conditions, certified by TÜV Rheinland®
  • Hybrid Permanent Magnet Motor (HPM)
    100% maintenance-free HPM motor with no bearings, pulleys, belts or couplings to wear out. Provides virtually unlimited starts and stops.
  • Rugged Reliability
    Designed for continuous operation at temperatures up to 46ºC (115ºF)
  • Advanced Ultracoat Protection
    Molecularly-bonded UltraCoat coating on rotors and air passages delivers increased uptime and reduced energy costs
  • Built to Save Energy
    The Nirvana HPM motor requires significantly less power at start-up, never operates at more than full-load amps and shuts down at minimum speed reducing wasted energy
  • Triple Inlet Cooler
    Eliminates the need for an expensive pre-cooler and maintains the optimum cooler operating temperature
  • Flexible Design
    Air or water-cooled options available

37-160kW Variable Speed Drive Oil Free Air Compressors Brochure