Air Compressors and Treatment Equipment

Air compressors and treatment equipment at Ritchie Bros.

Whether you're running a job site, a fabrication shop, a pipeline crew, or a sandblasting operation, reliable compressed air is non-negotiable. Our air compressor auctions cover the full range — towable diesel rotary screws, electric stationary units, hydraulic-driven compressors, plus the dryers, filters, and aftercoolers that keep that air clean and usable. New listings come through weekly across the U.S., Canada, Europe, and Australia, so you can browse used air compressors for sale alongside near-new units that still have years of service life left in them.

Rotary screw vs reciprocating: which one fits the job?

Most of the inventory you'll see on rbauction.com falls into one of two designs, and the right choice depends on duty cycle and air demand.

Rotary screw compressors are built for continuous duty. Two intermeshing helical rotors compress air smoothly, with far less heat and vibration than a piston-driven unit. If you're feeding pneumatic tools on a paving crew, running a blast pot, or supplying a plant that needs steady CFM all shift long, a used rotary air compressor is what you want. Look for towable diesel models from Atlas Copco (XAS, XATS series), Sullair (185, 375, 750H), Ingersoll Rand (P185, P375, P600), Doosan/Bobcat Portable Power, and Kaeser.

Reciprocating (piston) compressors work well for intermittent duty — service trucks, small shops, tire crews. They're cheaper to acquire and easier to rebuild, but they run hotter and shouldn't be pushed past a 60–70% duty cycle.

Towable and hydraulic-driven units

Pull-behind air compressors are the workhorses of road construction, utility work, and remote job sites. A 185 CFM unit handles one or two 90-lb breakers; step up to 375 CFM for sandblasting, larger pneumatic tools, or multiple operators; 750–1600 CFM units feed pipeline work, directional drilling, and well service. Check the receiver tank, the trailer DOT package, and the engine — Kubota, John Deere, Cat, and Isuzu diesels are common and parts are readily available.

Used hydraulic-driven air compressors for sale are a niche but valuable segment. Mounted directly on service trucks, crane bodies, or skid units, they run off the host vehicle's hydraulic system — no separate engine to maintain. VMAC, Boss Industries, and Vanair dominate this category.

Treatment equipment: don't overlook it

Compressed air is only as good as what comes out of the line. Our listings regularly include refrigerated and desiccant air dryers, coalescing and particulate filters, aftercoolers, condensate drains, and receiver tanks. If you're running pneumatic instrumentation, paint application, food-grade processes, or anything requiring ISO 8573-1 air quality, treatment equipment isn't optional. Names to look for: Atlas Copco FD and CD series, Ingersoll Rand D-EC, Kaeser KRD, Hankison, and Donaldson Ultrafilter.

What to look for when buying a used air compressor

• Airend condition: On rotary screw units, the airend is the most expensive component. Ask for the latest oil sample analysis if available, listen for bearing whine on startup, and check discharge temperature — anything consistently above 220°F suggests trouble.
• Hours vs maintenance records: A 6,000-hour Sullair with a documented service history beats a 2,500-hour unit with no paperwork. Look for filter, separator, and oil change intervals being met.
• Oil carryover and separator element: Excessive oil downstream of the compressor points to a tired separator or scavenge line issue. Pop the discharge line and look — a heavy oil film is a red flag.
• Engine and cooling package (towable units): Inspect the radiator core for bent fins and packed debris, check coolant condition, and confirm the engine starts cleanly without excessive smoke. Replacing a cooling package on a 375 CFM tow-behind isn't cheap.
• Trailer, axle, and DOT items: Brakes, lights, tires, and the tongue jack all need to be road-legal. RBA inspection reports flag these but verify before bidding.
• Pressure switches, unloader, and controls: Cycle the unit through load and unload if possible. Erratic pressure behavior often means a worn inlet valve or a failing control solenoid.

Pair it with the right support equipment

Buyers picking up a compressor often need adjacent equipment in the same auction — a light tower, a generator set, or a welder for the same crew. It's worth checking those categories before the sale closes.

Buy used air compressors at Ritchie Bros.

Every air compressor auction on rbauction.com and IronPlanet.com includes detailed inspection reports, photos of the airend, engine, and cooling package, and hour readings you can verify. You'll find Atlas Copco, Sullair, Ingersoll Rand, Doosan, Kaeser, and VMAC units coming through regularly, from 185 CFM tow-behinds to 1600+ CFM high-pressure rigs and stationary plant compressors. Browse current listings, register to bid, and pick up the air compressor deals that fit your operation — no rental commitments, just outright ownership.