Single Stage Liquid Ring Compressors

GARO AM2500 Single-Stage Liquid Ring Compressor

GARO liquid ring compressors are custom built for highly toxic, explosive and corrosive processes. They can handle dry and wet gases including ethylene, chlorine, H2S and many other condensable and non-condensable gases.


GARO AM and ASM Single-Stage Liquid Ring Compressors reach pressures up to 6 bar abs (72 psig) and are ideal for demanding process applications in petroleum refining and chemical plants. ASM models are specifically engineered for handling chlorine compression.

  • Suction Capacity: 100 to 5,000 m3/h (60 to 2,900 CFM)
  • Discharge Pressure: to 6 bar abs. (72 psig)
  • Single Mechanical Seal: Single, Double, Cartridge
  • Single Stage Design
  • Low Maintenance Liquid Ring Technology
  • Double Eccentric Casing for Ideal Rotor Balance
  • Overhung impeller with Minimal Rotating Parts
  • Customized for Every Application 

Advantages of Liquid Ring Technology

In a liquid ring compressor, liquid is used as the compressant with no metal-to-metal wearing surfaces. The only wearing parts are bearings and mechanical seals - making a GARO liquid ring compressor practically maintenance free. While other compressor technologies have wearing metal pistons, vanes, lobes or screws, the GARO liquid ring offers ongoing reliable performance without the high maintenance that comes with metal wearing components.

With GARO Liquid Ring Technology the effects of erosion, corrosion, vibration and noise are minimized.  
The liquid can be water, sulphuric acid, amine, crude oil or almost any liquid that does not react with the process gas, and is compatible with the metallurgy of the compressor.

The rugged design of GARO compressors offers reliable, low maintenance operation that is ideal for safe handling of wet, toxic, corrosive, flammable or explosive gases.

GARO Liquid Ring Compressor Design

GARO compressors are custom tailored for every application, and optimized for efficient performance. They meet design specs while maintaining a simple design and rugged construction which requires little maintenance. 

  • CASING WITH DOUBLE ECCENTRICITY   - Allows for perfect balancing of radial forces on the rotor
  • OVERHUNG IMPELLER   - Requires only 1 mechanical seal, reduces maintenance needs and time
  • FRONT PULL OUT   - Reduced maintenance
  • CONICAL DISTRIBUTION   - The circulation of the seal liquid is by pressure differential - No re-circulation pump is required. 
  • AXIAL REGULATION OF THE ROTOR -   Easy check and adjustment of the impeller clearance (only two wrenches and one dial gauge are required) 
  • TAILOR MADE DESIGN   - optimized efficiency and performance through modifications to the conical distributor, casing and/or impeller

Performance Map

Performance map showing GARO Single State Liquid Ring Compressors


GARO liquid ring compressors offer a rugged design that is tolerant to carryover from process upsets. They are ideal for the most demanding oil & gas, petrochemical and chemical applications including flare gas recovery, vapor recovery and compression of explosive and caustic gases.

Gases & Service Liquid

GARO liquid ring compressors offer reliable, low maintenance operation and are cool-running, making them ideal for handling the most demanding process and waste gases including:

  • Wet Gases - without the need for upstream dehydrating plants. With liquid as the compressant, GARO compressors can tolerate liquids in the suction stream
  • Gases with Fractions of Solid Elements - such as carbon powder or particles in the gas stream. There are no metal-to-metal wearing components in GARO's liquid ring technology, and the liquid is constantly circulating, washing out solid particles as it compresses the gas.
  • Toxic, Corrosive, Flammable, Explosives Gases - GARO liquid ring compressors are cool running, and offer safe handling of toxic, corrosive, flammable or explosive gases.

Gases Handled by GARO Compressors

BF3(Boron fluoride)

Blow down gases (mixed HC)

Flare gas

Methane - CH4

Carbon Dioxide

Carbon Monoxide

Dry Chlorine

EDC - C2H4Cl2

Ethylene - C2H4

Hydrogen - H2

Hydrogen Sulfide - H2S

Hydrochloric Acid (Dry) - HCl

Hydrochloric Acid (Wet) - HCl


Olefins (propylene ethylene recovery)

Vinylchloride VCM - C2H3Cl

Vent gas

Wet Chlorine

Service Liquid


Water / Gasoline / Amine

Water / Gasoline / Amine




96-98% Sulphuric acid


Acetic acid

Water / Solvent

Water / Amine

96-98% Sulphuric acid


Nitric acid + water



EDC / Water


Compressor Testing & Certification

Every GARO compressor receives rigorous testing and certification before shipment. Our test lab has state of the art equipment, and we hold our compressors to the highest industry standards

The GARO test lab at our company headquarters in Monza, Italy includes:

  • Four test beds, up to 1.3 MW (1750 HP) and frequencies from 45 to 62 Hz.
  • A 900 kW variable frequency driver (VFD) is also installed for special purposes.
  • Testing is according to ISO 1217, HEI, API 681, and Pneurop.
  • ASME PTC 10 is the common Standard for centrifugal compressors.
  • The flow nozzles are to ISA 1932.
  • Vibration, with the relevant spectrum, are picked up and recorded according to API 681.
  • The operation data are taken in real time and monitored through a LabVIEW program.
  • All instruments are calibrated per ISO 9001 Quality System.
  • Additional testing and analysis are available, including simulation of specific site conditions. Contact Garo to discuss recommending testing for your specific application or site location. 

Liquid Ring Working Principle