ABAC AS-7.5251TM 7.5 HP Rotary Screw Air Compressor - 131 Gallon Tank Mount, 125 PSI, 30.5 CFM, 67 dBA

The ABAC AS-7.5251TM is the 125 PSI, 131 gallon tank mount build of the 7.5 HP machine in the AS-B screw range. It delivers 30.5 CFM at a 125 PSI maximum and runs at 67 dBA, quiet enough to sit in the work area instead of a separate compressor room. This is the higher airflow setting offered on the 7.5 HP air end, so it is the one to specify when the shop is short of air rather than short of pressure. The air end and the receiver arrive as one assembled package on a 76 x 24 in footprint, so there is no separate tank to source, set and plumb. At 655 lbs it is the large receiver option in the 7.5 HP family, the one to buy when demand is intermittent and you want the compressor to run longer and rest longer rather than load and unload all day. Choose 230V single-phase (AS-7.5251TM) or 208-230-460V three-phase (AS-7.5253TM).

Key specifications

• Models: AS-7.5251TM (part number 4152044123) and AS-7.5253TM (part number 4152043893)
• Motor: 7.5 HP, energy efficient
• Air delivery: 30.5 CFM
• Maximum working pressure: 125 PSI
• Noise level: 67 dBA
• Mounting: tank mount on a 131 gallon air receiver
• Power supply: 230/1/60 or 208-230-460/3/60
• Weight: 655 lbs
• Dimensions (L x W x H): 76 x 24 x 63 in
• Eco-friendly vertical oil separation technology
• Digital controller with menu driven access for optimizing operating performance
• Brand: ABAC, part of the Atlas Copco group

Why a screw instead of another piston

A piston compressor builds air in bursts and needs time to cool between them. A rotary screw is rated for continuous duty, so it holds a flat line pressure through a full shift instead of sagging and recovering between jobs. That is the reason shops using air most of the day move off a reciprocating machine that is cycling hard, running hot and filling the room with noise. The AS-B air end limits air loss by design, and ABAC pairs it with an energy efficient motor and a digital controller, so the operating menus and the service intervals sit on the panel rather than on a clipboard. The trade is that a screw dislikes short cycling, which is exactly what the 131 gallon receiver underneath it is there to prevent.

How it compares

Across the AS-B range pressure, airflow, receiver size and mounting all move independently. The AS-7.5501TM is the identical 655 lb package set for 150 PSI, trading 3.4 CFM of airflow for the extra pressure. If floor space is the constraint, the AS-7.5251TM7 carries the same 30.5 CFM on a 71 gallon receiver at 507 lbs and a 63 x 23 in footprint. The AS-7.5251TMD is this same 131 gallon build with a refrigerated dryer already integrated at 741 lbs, which saves plumbing a separate dryer in. If you already own a receiver, the AS-7.5251BM is the bare 360 lb base mount at the same pressure and airflow. Stepping down, the AS-5251TM gives 20.3 CFM at a quieter 63 dBA; stepping up, the AS-10253TM carries 36.4 CFM at 69 dBA on the same receiver. Buy pressure only to the level your highest tool actually needs, because every step up costs airflow.

Typical applications

Automotive and fleet service bays, tire and truck shops, small production and fabrication floors, cabinet and woodworking shops, plasma tables, packaging lines, and any operation where a piston compressor is cycling too hard to keep up. At 30.5 CFM it will keep a pair of air ratchets, an orbital sander or a continuous blow off fed through a shift without the line pressure sagging. The 131 gallon receiver stores well over twice the air of the 71 gallon build, which matters when several bays hit the header at once or when a single large tool draws a short, heavy burst. The tank mount build is the one to buy for a shop starting its compressed air system from nothing, because the receiver, the mounts and the interconnecting pipe are already done and the installer only has to land power and tie into the header.

What to pair it with

Give the cabinet about 3 feet of clear air on the cooling side, keep it out of a hot corner, and run it on its own circuit sized to the motor nameplate. Oil, oil filter and separator element are the service items, and the digital controller tracks the intervals. Air leaving any screw carries moisture, so if it goes to paint, tires, pneumatic controls or anything that hates water, put a refrigerated dryer behind it. At 30.5 CFM the ABAC COOL 35 is the matching size and the COOL 50 leaves headroom for a later expansion, and both run on 115V so they sit beside the compressor without new wiring. See the rest of our rotary screw air compressors and the full refrigerated air dryer range. Call us with your tool list and duty cycle and we will confirm receiver sizing, connection sizes and installation clearances before you pipe it in.

CFM measured per ISO 1217 Annex C, quoted at 109 PSI for 125 PSI maximum units. Noise measured per ISO 2151:2004 using ISO 9614/2 (sound intensity method).