The Quincy QSI-675 is an industrial rotary screw air compressor built as a straightforward, serviceable package for plant-wide compressed air. This lot includes two 2015 Quincy QSI-675 units, offered together. Quincy rates the QSI-675 at 675 acfm at 110 psig full-load pressure, with a 125 psig maximum pressure, driven by a 150 HP, 1800 RPM motor. Each unit is an open-frame compressor package mounted on a heavy steel skid alongside twin-tower air treatment vessels and inline filtration, so the compressor and its air treatment move and set as one assembly. The QSI series design uses triplex discharge-end bearings, a full-flow fluid pump, two-stage air/fluid separation, an aftercooler, and auto-dual control with modulation to match output to plant demand. Combined, the pair is rated for 1,350 acfm at 110 psig.
A matched pair of rotary screw compressors is a step up from a plant that leans on a single compressor or on older reciprocating piston units. Rotary screw compression is designed for continuous duty, delivering steady, pulsation-free air for CNC machining centers, lathes, air tools, and automation, where piston compressors are built for intermittent cycles. Two identical QSI-675 units add flexibility a single machine cannot: run both for full combined capacity during peak demand, or run one while the second stands by for scheduled maintenance, so service on one compressor does not have to shut down shop air. Identical models also simplify spare parts, filters, and fluid, since one service plan covers both units. For a shop growing its air demand, or a plant that wants redundancy built in, this lot delivers 150 HP-class capacity times two on skids that keep each compressor and its air treatment together.