This page lists compressors rated roughly 225 to 274 CFM, in two groups. Plant machines: the Atlas Copco GA37 50 HP at 239 CFM and 125 PSI, the GA37 VSD 50 HP at 247 CFM, the GA30 VSDS 40 HP at 234 CFM, the Quincy QGSV-60 variable speed at 247 CFM and 125 PSI, the Chicago Pneumatic CPVSM 50 and 60 HP variable speed at 236 and 263 CFM, and the CPCG 60 HP gear driven screw at 263 CFM in 100 to 175 PSI builds. Jobsite machines: the Atlas Copco XATS 250 KD8 and Chicago Pneumatic CPS 250 KD8 diesel towables, both 250 CFM on a Kubota engine, the CPS with multi pressure control up to 150 PSI.

What 250 CFM supports

On a jobsite, 250 CFM is the blasting compressor: it holds a 3/8 inch nozzle at 100 PSI with reserve, or runs three 60 pound breakers, or a drill rig and a breaker together. In a plant, 250 CFM covers 70 to 85 air stations, a large body shop with a downdraft booth, a plastics plant with several molding machines, or a foundry core room.

Towable or stationary

The XATS 250 and CPS 250 have their own engine, fuel tank and running gear and can be ordered with an aftercooler and water separator for blasting and painting. The stationary 50 and 60 HP screws need 460 volt three phase service and a compressor room, and cost far less per CFM over a shift. Buy the towable for construction and field blasting; buy the stationary screw for anything under a roof.

Fixed speed or variable speed in the plant

The GA37 and CPCG 60 are fixed speed. The GA37 VSD, GA30 VSDS, QGSV-60 and CPVSM 50 and 60 are variable speed and pay for themselves in plants that run below 70 percent load for part of the day. Get a load study before choosing fixed speed at this size.

Power and installation

A 60 HP motor draws about 77 amps at 460 volt three phase or 154 amps at 230 volt; a 50 HP motor draws about 65 amps at 460 volt. Plan on a dedicated feeder, a room with ducted cooling air rated for 8 to 10 kW of rejected heat, and a receiver of 240 to 400 gallons.

Dryer sizing

Pair a stationary 250 CFM compressor with a 300 CFM refrigerated air dryer, or a cycling dryer when demand swings. Field blasting needs a desiccant dryer or at least an aftercooler and separator ahead of the pot.

Related pages

• 200 CFM air compressors
• 375 CFM air compressors
• Towable air compressors
• Variable speed rotary screw air compressors
• Shop all sizes by CFM