Screw Compressors Oil-Free Screw Gas

Kobelco oil-free screw gas compressors are designed to satisfy the latest API 619 (rotary-type positive displacement compressors for petroleum, chemical and gas industry services) requirements for service in heavy and continuous duties. They are intended to deliver years of continuous, uninterrupted operation.


Oil-free screw gas compressors are suitable for complex and dirty gas services, such as offshore vapor recovery, refinery flare gas recovery and petrochemical polymer forming gas. Kobelco supplies the most advanced oil-free screw gas compressor, with the world’s largest capability - up to 142,000 m3/hr (84,000 cfm). Kobelco oil-free screw gas compressors are contributing to environmental protection by recovering dirty gases that were formerly flared to the atmosphere.

Inlet volume flow range: up to 142,000 m3/h (84,000 cfm)
Discharge pressure: up to 45 barg (640 psig)

Key Advantages

  • Oil-free operation is great for handling corrosive gases
  • Insensitive to changes in gas composition
  • Easy to maintain

Any Gas Can Be Compressed

Kobelco oil-free screw compressors handle complex and dirty gases. They can tolerate polymers formed in the casing or on rotors - unlike centrifugal or reciprocating compressors. Kobelco screw compressor rotors have rigid shafts and operate at lower speeds than the first lateral critical and are insensitive to vibration due to imbalance. Foreign matter sticking to the rotors after some duration of operation even increases efficiency, due to decreased inter-lobe leakage. In some cases, water is injected to control discharge temperature or solvent is injected to soften and remove the polymer, which could otherwise become hard and adversely affect the compressor or process.

Robust Design

API 619 Construction
Kobelco oil-free screw compressors are designed to API619 standards.

Reliable at High Temperatures
Kobelco Oil-Free Screw compressors can handle high-temperature gas by the following unique designs:

  1. Casing Cooling Jacket, which prevents thermal distortion
  2. Internal Rotor Cooling, which maintains inter-lobe clearances at high temperatures