ABAC AS-20753BM 20 HP Rotary Screw Air Compressor - Base Mount, 175 PSI, 48.5 CFM, 71 dBA

The ABAC AS-20753BM is a 20 HP rotary screw air compressor built for shops that need 175 PSI held steady all shift rather than recovered between jobs. It delivers 48.5 CFM free air delivery at a 175 PSI maximum and runs at 71 dBA. This is the base mount version, so it ships without a tank and plumbs into an air receiver you already own or one sized to your demand. Power is 208-230-460V three-phase.

Key specifications

• Model: AS-20753BM (ABAC part number 4152043917)
• Motor: 20 HP, energy-efficient, 208-230-460/3/60
• Air delivery: 48.5 CFM free air delivery, measured to ISO 1217 Annex C
• Working pressure: 175 PSI maximum
• Noise level: 71 dBA, measured to ISO 2151:2004 using ISO 9614/2
• Mounting: base mount, no tank and no dryer
• Weight: 520 lbs
• Dimensions (L x W x H): 37 x 28 x 40 in
• Fully integrated aluminum block airend
• Vertical oil separation technology for low oil carryover
• Digital controller with programmed maintenance menus

Inside the AS-B airend

ABAC builds the AS-B range around a fully integrated aluminum block airend, an energy-efficient motor and vertical oil separation technology. The design targets limited air loss, low oil carryover, long service life and low noise and vibration, which is what lets a screw run loaded through a full shift where a reciprocating machine would be heat soaked and cycling. The digital controller handles start and stop and load and unload, and carries menu driven programmed maintenance, so service intervals are tracked by the machine rather than guessed at. ABAC designs the AS-B cabinet as one of the smallest footprints in its class, which is why a 20 HP machine fits a 37 by 28 inch plan.

What 175 PSI costs you

Pressure and flow trade against each other on the same 20 HP motor. The 125 PSI AS-20253BM gives 60.6 CFM, the 150 PSI AS-20503BM gives 54 CFM, and this 175 PSI build gives 48.5 CFM. That is roughly 12 CFM given up against the 125 PSI machine for 50 PSI of extra headroom, on a cabinet that weighs 520 lbs instead of 516 and occupies the same floor plan. Specify 175 PSI when a tool, a press or a process genuinely needs the pressure at the point of use, not as insurance against undersized piping. If the line pressure problem is actually pressure drop, larger pipe is cheaper than 12 CFM.

How it compares

Stepping down, the 15 HP AS-15753BM delivers 41.7 CFM at the same 175 PSI and 69 dBA, in the same 37 by 28 inch cabinet, so the choice between them is purely airflow rather than floor space. If you want the receiver and the plumbing solved in one purchase instead, the tank mount AS-20753TM puts the same airend on an ASME receiver at 818 lbs, and the tank mount with integrated dryer AS-20753TMD adds moisture control on the same base.

Base mount or tank mount

Base mount is the starting point for a modular compressed air system. You pick the receiver, you pick where it sits, and you can oversize the tank to smooth a peaky demand profile without buying a bigger compressor. A shop that draws air in heavy bursts, a blast cabinet or a press that cycles hard, benefits more from stored air than from extra CFM, and on a base mount build that choice stays yours. It also means the compressor can sit close to the point of use while the receiver lives wherever there is room for it.

Planning the installation

Leave clearance around the cabinet for cooling airflow and keep front access clear for service. Run the machine on a three-phase circuit sized to the motor nameplate, and confirm which of the 208, 230 or 460 volt taps your panel supplies before the electrician arrives. Oil, oil filter, air filter and separator element are the consumables on a screw compressor, and keeping a set on the shelf is what stops a routine service from becoming downtime. At 520 lbs this is a forklift or pallet jack delivery, not a two-person lift.

Drying the air it makes

A rotary screw delivers warm, saturated air, and 48.5 CFM of it will carry a lot of water into your lines if nothing removes it. Size a refrigerated dryer above the compressor's output rather than level with it, so the dryer is not working at its limit on a hot day. The ABAC COOL 65 refrigerated air dryer sits comfortably above this machine's 48.5 CFM, and the rest of the sizes are in the ABAC COOL dryer range. Check the dryer's maximum working pressure against your 175 PSI line before you specify, and add a filter ahead of any finishing, instrument or breathing-adjacent air.

Typical applications

Production and fabrication floors, multi-bay automotive and fleet service, tire and truck shops, cabinet and woodworking plants, blast and finishing booths, and any operation running high pressure tooling where a reciprocating compressor is loaded most of the shift just to hold line pressure. A rotary screw is built for continuous duty, so it keeps a steady line pressure through the whole shift instead of recovering between jobs. At 48.5 CFM and 175 PSI this machine will carry several high pressure tools at once, which is usually the point at which a plant stops adding piston compressors and consolidates on one screw.

Part of the ABAC AS-B screw range from the Atlas Copco group. See the rest of the rotary screw air compressors and our wider range of stationary air compressors.

CFM quoted as free air delivery, measured per ISO 1217 Annex C. Noise measured per ISO 2151:2004 using ISO 9614/2 (sound intensity method).