Quincy 4152028076 QGS 40 HP Tankless Rotary Screw Air Compressor

The defining fact about this machine sits in the spec sheet rather than the marketing copy: its tank size is recorded as 0 gallons and its tank-included field reads "No". This is a bare rotary screw package — an airend, a motor and a control cabinet, with nothing bolted underneath to store air in. Buying it means you already own, or are about to buy, the receiver it feeds.

That is how plants normally purchase air at this size. Above roughly thirty horsepower the receiver stops being an accessory and becomes part of the building: it is sized to the demand profile of every machine on the header, sited where the pipework wants it, and shared. A 40 HP airend welded to whatever tank a catalogue happened to pair it with is the compromise. This is the version that does not make you accept one.

Gear drive, and what it removes from your maintenance list

The pump drive on this unit is recorded as a gear drive. On a belt-driven screw compressor the belts are a wear item with a schedule attached: tension them, check them, and eventually replace a matched set, with the machine off and the panels open each time. A gear train has none of that. The motor and the airend are coupled through hardened gears running in the same lubricant that serves the rest of the pump, so the transmission is maintained by the oil change you were doing anyway.

There is a second, quieter benefit. A slipping or mis-tensioned belt loses power between the motor shaft and the airend, and that loss is invisible — the machine still runs, it just makes less air for the same electricity bill. Gear coupling removes that failure mode entirely, which matters more on a unit expected to run continuously than it does on one that starts a few times an hour.

Continuous duty is a design decision, not a rating

The duty cycle here is 100%. A reciprocating compressor is normally sized to run part of the time and cool off for the rest; ask it to run flat out and you shorten its life. A rotary screw compressor is built the other way round — it is happiest loaded and running, and the oil-injected screw element is cooled by the same fluid that seals and lubricates it. If your air demand is steady rather than peaky, this is the machine architecture that suits it.

The enclosure is rated at 71 dBA. That is quiet enough to stand next to and hold a conversation, which is the practical test that matters when the compressor is inside the working area rather than in a plant room down the corridor.

Will it fit, and what will it cost you to feed?

The cabinet measures 44.5" long, 30.7" wide and 49.2" tall, and the unit weighs 979 lbs. It is short — being tankless, there is no horizontal receiver stretching the footprint out — but it still needs service clearance on the door side and space for the cooling air to leave. Check the hinged doors and detachable panels can actually open where you intend to stand it, not just that the box will squeeze in.

Power is the part to settle before you order. This is a 230/460V 3-phase machine and it requires a Wye-Delta reduced-voltage start. Quincy's own data does not publish an amp draw or a recommended breaker size for it; both fields read "Consult Certified Electrician". We are not going to invent numbers Quincy declined to print. Have a licensed electrician confirm your service capacity, your feeder sizing and your starter arrangement against the unit's nameplate before the machine ships, because a 40 HP three-phase load is not something to discover a problem with on installation day. Site preparation, electrical supply and any permits are the customer's responsibility.

What to confirm about the dryer and the certification

Published information for this compressor differs on two points. Each is attributed to its source below.

The manufacturer's feature list for this compressor includes "Integrated Refrigerant Air Dryer"; the specification table on this page has an Air Dryer field, and it reads "No". If a built-in refrigerated dryer is the reason you are considering this unit, confirm it with us in writing before you commit — we will check it against the current Quincy factory order sheet.

The specification table also records a certification of ASME, which is the American pressure-vessel code and applies to air receivers, while this unit is listed as having no receiver — the field may have been carried over from a tanked model in the same family. Ask us before ordering if the marking matters to your inspection regime.

Note also that ASME is a pressure-vessel code. It is not an electrical safety listing, and it does not stand in for one. If your insurer, your local inspector or your plant's own standards require a North American third-party electrical listing on the control panel, verify that requirement against the machine's nameplate before purchase rather than after.

Perfect for

Manufacturing and fabrication shops with an existing receiver and air-treatment train that need to replace or add compressor capacity without re-plumbing. Multi-bay commercial service operations running production air all day. Any facility whose air demand is steady enough that a continuously running screw machine is cheaper than a large reciprocating unit cycling on and off. It is not a home-garage compressor, and it is not a plug-in machine.

Specifications

One figure we have deliberately left out: the free-air-delivery rating. The figure published for this product carries no unit of measure, so it is not printed here as CFM. Ask us and we will read it off the current Quincy datasheet for you.

What's included

The manufacturer's feature list covers the QGS gear-driven rotary screw compressor itself, the Infologic2 Basic Controller with its display panel, the 100% duty-cycle TEFC motor with IP 55 wash-down protection, an air filter, a pressure gauge, an oil sight glass, an aftercooler, low-oil shutdown on both engine and pump, and a spin-on fluid filter. A magnetic starter is listed as included. A receiver tank and an electronic drain valve are not. The refrigerant dryer is the disputed item described above.

Shipping and delivery

This compressor moves as freight to the lower 48 states, and freight is quoted live at checkout for your address rather than baked into the page. At 979 lbs it is beyond what a delivery driver will hand down: you need a dock, a forklift, or you take the shipment at the carrier's terminal. Delivery to a residential address carries a residential fee. When the truck arrives, walk the crate before you sign — look at the panels, the base and the cabinet corners, and write any damage you find on the bill of lading. A clean signature is the carrier's evidence that the machine arrived intact, and it is very hard to argue with afterwards.

Warranty

Quincy's recorded terms for this unit are 1 Year consumer and 1 Year commercial coverage as standard. An extended 3 Year factory warranty is available, and the True Blue 5-Year warranty applies where the machine is commissioned by a Quincy authorized start-up. Registration and start-up conditions are the manufacturer's, so read the warranty handbook before the installer leaves site rather than after. If you think you have a warranty fault, stop the machine and call us before anything is opened up — a unit that has been partly disassembled is a much harder claim to make, and on a compressor this size that is not a small thing to lose.