Quincy 4152021976 QGS 15 HP 120 Gallon Rotary Screw Air Compressor

This is the version that arrives without air treatment, and that is a specification rather than an omission. Its data lists no refrigerated dryer and no aftercooler: what leaves the receiver is compressed air, and whatever you do to it afterwards is yours to choose. Every other 120 gallon package in this range arrives with drying built in.

There are two good reasons to want it this way. The first is that a great many shops upgrading a compressor already own a dryer and filter bank on the header, sized and plumbed, and buying a second one inside a cabinet is paying twice for the same job. The second is that dewpoint requirements vary enormously — instrument air, plasma cutting, powder coating and general shop air are not the same problem, and a packaged dryer is sized for the average of them. Specifying your own lets you hit your actual target rather than the one the factory assumed.

The corollary, and we would rather be blunt about it: if you do not already have air treatment, you need to plan for it. Untreated compressed air carries water, and water in a header will rust pipework, wreck air tools from the inside and mark a finish coat. That is not a criticism of this compressor, it is a description of physics. Ask us and we will help you size a dryer to sit downstream of it.

54.9 CFM at 125 PSI, continuously

Output is 54.9 CFM at 125 PSI, held at a 100% duty cycle. The duty cycle is the number that changes how a shop works. A large reciprocating compressor publishes an output it can only sustain in bursts, so a busy morning turns into a queue: two technicians on air tools and everyone starts watching the gauge. A screw element at full duty simply keeps producing, and the compressor stops being something the day is planned around.

At this level you can run several bays of impacts, ratchets, air hammers and blow guns simultaneously, keep a sander or a blast cabinet going, and still have pressure at the far end of the shop. It is a proper commercial supply rather than a large domestic one.

Auto-Dual, and the cost of a machine that never stops

The Auto-Dual control system allows programmed timed shutdowns. On a compressor rated to run continuously that is the most valuable control on the panel. Left alone, the machine does what it was designed to do: hold pressure through the night in a building where nobody is drawing a cubic foot of air. That idle is invisible on the shop floor and entirely visible on the electricity bill. Programming it out costs nothing and is the single easiest saving available on a unit of this type.

Belt drive, and the rest of the mechanicals

Drive is by long-life V-belt. It is a wear item and we will not pretend otherwise — belts want a periodic tension and condition check, and eventually a replacement set. In exchange you get a transmission that is inexpensive, tolerant and simple to service, with parts that are not exotic. Other models in this QGS family are gear driven if you would rather have no belts on the list at all; ask us which.

Around it, the specification is built for long intervals rather than frequent attention. Premium synthetic lubrication is rated for 8,000 hours, which keeps oil carryover low and stretches the fluid service a long way out. The motor is TEFC, sitting in Quincy's standard quiet enclosure, and low-oil shutdown protects the engine and the pump. There is an oil sight glass for the routine check. One thing to note: unlike several units in this range, this model's specification table does not list a pressure gauge — if you want one at the receiver, raise it with us before you order.

Will it fit, and can your supply carry it?

The package measures 76 inches long, 25 inches wide and 58 inches tall, and weighs 815 lbs. It is the long, low arrangement — a horizontal 120 gallon receiver with the compressor mounted above it — so the constraint is usually the run of wall you can give it rather than ceiling height. At 25 inches wide it fits down the side of a bay where a tall cabinet would not. Leave clearance at the service end. The receiver outlet is 1/2-inch, and that is where your header sizing begins.

The electrical side is not optional homework. This is a 208-230/460V 3-phase machine with a magnetic starter fitted, and it needs a licensed electrician on site. Quincy publishes neither an amp draw nor a recommended breaker size for it — both entries read "Consult Certified Electrician" — and we will not manufacture a figure to fill the gap. Get the service, feeder and disconnect sized against the nameplate before delivery day. Electrical supply, siting and permits are the customer's responsibility.

Perfect for

Shops that already run their own dryer and filtration and want compressor capacity, not a duplicate treatment train. Fabrication and machining operations with a specific dewpoint requirement they intend to spec themselves. Multi-bay service shops replacing a tired reciprocating unit. Facilities with three-phase power and a long wall to put a horizontal package against.

Specifications

No sound rating appears above, and that is deliberate. The noise figure held in this product's data has no unit recorded against it, and an unlabelled number is not a specification we will publish about a machine that may end up beside people all day. Ask and we will read the current figure from Quincy's datasheet.

What's included

Per the manufacturer's feature list and specification table: the QGS rotary screw compressor with long-life V-belt drive, the 120 gallon horizontal receiver, the TEFC electric motor, the standard quiet enclosure, Auto-Dual control, an air filter, an oil sight glass, low-oil shutdown on engine and pump, a magnetic starter and a factory fill of premium synthetic lubricant. Not included, and worth repeating because it is the defining feature of this part number: a refrigerated dryer, an aftercooler and an electronic drain valve.

Shipping and delivery

Shipped as freight within the lower 48 states, with the cost calculated live at checkout for your specific address. We do not print a freight figure on the page — carrier pricing moves, and a number that has gone stale causes more trouble than it saves. Practically, 815 lbs on a long crate is past anything a driver can hand down, so have a dock, a suitably rated forklift, or arrange collection at the carrier's terminal. Residential addresses carry a residential fee. Look the crate over on arrival — base rails, panels, corners — and write any damage on the bill of lading before signing, because a clean signature is the carrier's record that it arrived in good order.

Warranty

Standard recorded cover is 1 Year consumer and 1 Year commercial. An extended 3 Year factory warranty is available for purchase, and the True Blue 5-Year warranty applies where the machine is commissioned by a Quincy authorized start-up — a condition of the cover rather than an optional visit, so arrange it with the electrical install. If you think you have a warranty fault, stop the compressor and contact us before anything is opened. A unit that has already been taken apart is a claim that becomes very difficult to support, and on a machine of this value that is not worth risking for an afternoon's curiosity.