ABAC AB7-21120D 15 HP Two-Stage Duplex Air Compressor - 120 Gallon Horizontal, 175 PSI, 44.6 CFM

The ABAC AB7 Duplex is the largest piston duplex in ABAC's Hybrid Pro range: two independent 7.5 HP motor and pump assemblies on one 120 gallon horizontal ASME tank, producing a combined 44.6 CFM at a maximum 175 PSI. Alternating operation spreads runtime evenly across both pumps, while simultaneous operation covers peak demand that would overwhelm a single-pump machine. The second reason shops choose a duplex is redundancy: if one pump comes out for service, the other keeps the line pressurized instead of shutting the floor down.

Key specifications

• Models: AB7-21120D 230V single-phase (part 8090304257), AB7-23120D 230V three-phase (part 8090304265), AB7-43120D 460V three-phase (part 8090304273)
• Power: 15 HP total, two 7.5 HP motors, 60 Hz
• Pumps: two T39 two-stage hybrid pumps, aluminum with cast iron cylinders
• Air delivery: 44.6 CFM combined at max pressure
• Maximum pressure: 175 PSI
• Tank: 120 gallon horizontal, ASME tank and safety valves
• Alternating or simultaneous pump operation for uptime and peak capacity
• Aluminum heads and aftercoolers, fully enclosed belt guards
• Dual pressure switch controls, magnetic starters
• Weight: 910 lbs | Dimensions: 25 x 79 x 55 in
• Warranty: 2 year full, assembled in the USA

How it compares

Within the Hybrid Pro duplex range the choice is capacity on an identical footprint. The AB5-21120D pairs two 5 HP pumps for 33.2 CFM on the same 120 gallon horizontal tank and the same 25 x 79 x 55 in floor space, so the AB7 buys roughly eleven more CFM without asking for another square foot of shop. Against a single machine, the AB7-2180V runs one 7.5 HP T39 pump at 22.2 CFM; the duplex doubles that and adds the fallback a single-pump compressor cannot give you. If the duty cycle is hard enough to want full cast iron rather than the hybrid T39, the ABC7-21120HD Ironman duplex is also 15 HP on 120 gallons, at 42 CFM with C1 cast iron pumps.

Typical applications

High-demand fabrication shops, collision centers running more than one booth, tire and fleet service bays, and industrial plants where sandblasting, plasma cutting, or several pneumatic stations draw at the same time. Those loads are the case for a duplex: demand arrives in surges rather than steadily, so one pump carries the baseline and the second joins only when the line calls for it, which keeps both motors off the short-cycling that shortens a single large compressor's life. Where the panel offers three-phase, the 230V or 460V three-phase build is the better long term choice, because a three-phase motor draws less current per leg and runs cooler under a hard duty cycle.

Two-stage compression sends warm, wet air down the line, so size a refrigerated dryer above the compressor's output rather than to the pipe. At 50 CFM the ABAC COOL 50 is the smallest dryer in the COOL range that covers 44.6 CFM with headroom. Part of ABAC's 2-Stage Hybrid Pro Duplex range from the Atlas Copco group. Browse the rest of our piston air compressors and our refrigerated air dryers.