Quincy 4152021972 QGS 10 HP Rotary Screw Air Compressor, 120 Gallons

The number that defines this machine is 38.8 CFM at 125 PSI, delivered on a continuous 100% duty cycle. Read those two facts together, because separately they mislead. Plenty of compressors will quote an airflow figure; far fewer are rated to produce it without stopping. A piston compressor advertising similar output is quoting what it can do during its pumping phase, and it must then rest. This rotary screw is designed to hold 38.8 CFM as a steady state, hour after hour. If you have ever watched shop pressure sag at 3pm on a busy day, that distinction is the one you are actually shopping for.

It is a 10 HP oil-injected rotary screw on a 120-gallon receiver, running a TEFC motor through a long-life V-belt drive, wired for three-phase power at 208, 230 or 460V.

Auto-Dual control, and why it is not just an on/off switch

The unit uses Auto-Dual control, which lets you set a timed shutdown rather than leaving the machine to idle indefinitely between demands. A rotary screw that runs unloaded still consumes real power — it is turning the airend and driving the cooling fan for no output. On a shop with irregular demand, the ability to say "if nothing has been drawn for this long, stop" is straightforwardly money. On a shop with steady demand, you set it long and the machine simply stays on load. One control, two very different operating profiles, and the choice is yours rather than the factory's.

Why a screw compressor tolerates continuous running

In a reciprocating pump, every stroke reverses the direction of a piston. That reversal is where the heat, the vibration and the wear come from, and it is why duty cycle is a limit rather than a footnote. A screw compressor has two rotors turning continuously in one direction, with oil injected to seal, cool and lubricate the compression. Nothing stops and reverses. The result is low vibration, a machine that can be sited without a heavy inertia base, and a duty rating of 100% that is a design property rather than an optimistic reading of a test.

Lubrication and downstream cleanliness

Premium synthetic lubricant rated for up to 8,000 hours does two jobs here. It stretches the service interval, and it keeps oil carryover low — important on a screw compressor, because oil is injected into the compression chamber by design and whatever is not separated out ends up in your air. Low carryover means less loading on downstream filtration and cleaner air at the tool.

Will It Fit?

• Footprint. 76" long by 25" wide. Narrow for the output, which is the point of a packaged screw compressor — but leave real clearance at the cooling air inlet and outlet and on the service side. Enclosure machines fail on airflow long before they fail on anything mechanical.
• Height. 58" overall.
• Weight. 775 lbs on a level slab.
• Power. Three phase, 208, 230 or 460V. Quincy publishes no amp draw or breaker size for this build and states plainly that it must be wired on site by a licensed electrician — take that at face value and get the electrician involved before delivery, not after.
• Air connection. A 1/2" tank outlet. At this airflow the pipe you run from it deserves proper sizing; a long undersized main will cost you more pressure than any component on the machine.

Slab, feed, disconnect, on-site wiring, air main and condensate handling are the customer's responsibility.

Perfect For

• Multi-bay service and tire shops where demand is constant and recovery time is the complaint.
• Light manufacturing and production cells running air tooling or actuators continuously.
• Facilities upgrading from a duty-limited piston compressor that keeps the shop waiting on pressure.
• Sites with varied shift patterns, where the Auto-Dual timed shutdown can be tuned to the working day.

What's in the Box

The compressor package as described: rotary screw airend, TEFC motor, V-belt drive, 120-gallon receiver, enclosure, Auto-Dual control and magnetic starter, with its synthetic lubricant charge. Site wiring, disconnect, shop piping, point-of-use filtration and regulation are not supplied. Please see the note below regarding the air dryer before you assume one is fitted. The packing list shipped with the unit is definitive.

Specifications

Certification, Honestly

Our record lists one certification for this unit: the ASME pressure-vessel code, covering the receiver. That is a genuine third-party construction and test standard for the tank itself, and nothing more than that should be read into it. It says nothing about the electrical assembly or the enclosure.

We hold no record of a further safety listing on this machine, and we are not going to imply one. This matters in practice, because some insurers, fleet policies and local jurisdictions require a specific third-party listing on permanently installed shop equipment before they will sign off an installation. If that is your situation, find out precisely which listing is required and check it against the unit's data plate before purchase. We will go through the factory documentation with you if it helps.

Before You Order — Please Confirm

• Whether an air dryer is fitted. This is the important one on this listing. The product feature list includes an integrated refrigerated air dryer. Our specification record for the same unit says the air dryer is "No". Those cannot both be true, and a dryer is not a detail — it changes the price, the footprint, the condensate handling and whether your air is fit for paint. We are therefore not claiming a dryer on this page, and we are not claiming its absence either. If dry air is why you are buying, contact us and we will confirm the exact build against the factory order before anything ships.
• Sound level. The machine has an enclosure designed to reduce noise and the current copy describes it as quiet, but the decibel figure in our data is not recorded against a unit of measure we can verify, so no number is published above. Ask us if a sound limit is a site requirement.

Shipping and Delivery

Freight to the lower 48 states, quoted live at checkout for your address. It ships as a 775 lb palletised unit, so plan the unload before it arrives: forklift, dock, or terminal pickup at the carrier's depot. A residential delivery address adds a residential fee, shown with the freight quote at checkout. Check the machine over on arrival — panels, receiver, feet, control head — and note any damage on the bill of lading before you sign it. Signing clean and calling later is the one sequence that reliably loses a freight claim.

Warranty

There are three tiers here and only one of them is automatic. The standard factory warranty is 1 year. An extended 3-year factory warranty is available. The True Blue 5-year warranty is offered with a Quincy authorized start-up — that is a condition, not a formality, so if the 5-year term matters to you, book the authorized start-up as part of the installation. Retro-fitting the paperwork after the machine has been running is not usually accepted.

If anything goes wrong, call us before the enclosure is opened and before anyone touches the airend. Disassembly ahead of a claim is the most common way a covered failure stops being covered.