Schulz 560HV20-1: an oil-free cast iron pump turning at 1,050 RPM

Most shop compressors put a film of lubricating oil between the piston rings and the cylinder wall, and a little of that oil leaves with the air. For a tyre bay it does not matter. For a dental surgery, a laboratory bench, a food area or a process where the air touches the product, it matters a great deal — and it is the reason this machine exists. The 560HV20-1 runs an oil-free cast iron pump, so there is no lubricant in the compression chamber to carry over in the first place.

It is a 5 HP unit on 230V 1-phase power with a 60-gallon horizontal steel tank, rated at 20 CFM at 90 PSI with a maximum of 120 PSI, and the pump turns at just 1,050 RPM.

Oil-free is a design, not a shortcut

There are two ways to build a compressor that does not put oil in the air. One is a pump of light materials with permanently lubricated parts and a short service life — the portable machine on a hardware-store shelf. The other is a proper cast iron pump with dry-running components, slowed down enough that the reduced lubrication is not asking the impossible. This is the second kind.

For an owner the difference is maintenance as much as air quality: no oil to check, none to change, no crankcase to drain, no used oil to dispose of, and no oil level to be caught out by on a machine tucked into a plant room. What remains is a tank that collects condensate and needs draining, and an intake filter worth watching — dry-running components are unforgiving about grit.

1,050 RPM is the specification that makes the rest possible

Pump speed quietly governs everything else. Each revolution is two direction changes, two valve events and a full sweep of the rings along the bore, and at high speed those events pile up into heat, wear and noise.

At 1,050 RPM this pump turns slowly for its output class, and that is what makes a dry-running design credible: less rubbing speed means less frictional heat, and heat is exactly what an oil-free pump has fewer defences against. Cast iron cylinders with deep fins and space between them shed what is still produced. Slow speed, iron mass and cooling area are one decision here, not three features.

The pressure trade-off, stated honestly

This machine tops out at 120 PSI, and its rated 20 CFM is quoted at 90 PSI. The oil-lubricated two-stage compressors in this range go considerably higher; if your work needs the top of that band — some plasma cutters, high-pressure test rigs — this is not the machine, and we would rather say so before you pay freight. For what it is built for, the ceiling is not the constraint: clinic air tools, blow-off and cleaning, pneumatic actuators, dental and laboratory equipment and most general shop work sit comfortably inside it.

Confirm the regulator before you order

Published figures for the regulator differ: the description on this page lists a built-in regulator switch among the features; the manufacturer specification field we hold for this model records the regulator as No.

Both are shown here, each attributed to its source. If a factory-fitted regulator is part of why you are buying — and on a machine feeding instruments or a clinic it very often is — contact us before ordering and we will confirm it with Schulz in writing. A regulator is straightforward to add downstream if it turns out not to be fitted, but you should know which you are getting.

Will It Fit?

• Floor: 66.9 inches long by 21.3 inches wide. Long and narrow, so it belongs along a wall or against a plant-room bulkhead rather than in a corner.
• Height: 40.6 inches — bench height. It goes under shelving, under a mezzanine and through most standard doorways on a pallet truck, which is a genuine advantage in a fitted-out building rather than an open workshop.
• Weight: 447 lbs. Schulz publishes no floor loading or slab specification for this model and none is invented here. In a plant room or on a ground-floor slab it is unremarkable; on a suspended floor, ask someone qualified before delivery.
• Power: 230V, 1-phase. Unusually for this range, Schulz does publish a figure here: a 40 Amp breaker is recommended. Treat that as the manufacturer's starting point and have a certified electrician confirm it against your conductor, run length and local code — the recommendation does not replace the calculation.
• Plumbing: a 1/2-inch tank outlet.

Confirming the space, the floor and the supply before ordering is the buyer's responsibility.

The tank is treated inside as well as out

Two details on this model are aimed squarely at the clean-air application. The steel receiver carries an internal antibacterial powder coating, and the construction is epoxy coated to resist corrosion of the pump and tank.

Both address the same problem. A compressor tank is a cool steel vessel full of humid air — a place where water collects and, given a surface, biological growth follows. In a workshop that shows up as rust flakes in the line; in a clinic or a food area it is a contamination question. Treating the inside of the vessel rather than only painting the outside is a considered choice for those rooms, and it does not remove your obligation to drain the tank regularly.

Perfect For

• Dental surgeries, clinics and laboratories where oil carryover is not acceptable at any level.
• Offices and fitted commercial premises, helped by the bench-height, low-profile package.
• Food handling, packaging and critical industrial processes where the air meets the product.
• Any shop that wants to stop doing oil changes on a compressor and is content with a working pressure in this band.

What Is Fitted

• Oil-free belt-drive cast iron pump, two-stage, 1,050 RPM
• 5 HP electric motor, 230V 1-phase
• 60-gallon horizontal steel air tank with internal antibacterial powder coating
• ASME safety valve and tank drain
• Built-in regulator switch (see the note above)
• Intake air filter
• Swedish steel valves
• Epoxy coated construction
• Pressure gauge
• 1/2-inch tank outlet

Specifications

Output

Motor, pump and power

Tank and dimensions

Certification, stated plainly

ASME is recorded for this compressor, covering the safety valve and the air receiver. It is a pressure-vessel standard, and it is the one to insist on for the part of a compressor that stores energy.

It is not an electrical safety listing and it does not certify the assembled machine, and that distinction is worth being deliberate about here rather than anywhere else in this range — a compressor destined for a clinic, a laboratory or a food area is far more likely to be inspected against a facility standard than one in a workshop. If a specific listing or approval is required by your regulator, insurer or client, ask us before ordering and we will confirm in writing exactly what this unit carries. We would rather lose the sale than have the machine fail an inspection after installation.

Shipping and Delivery

Ships by freight to the lower 48 states, quoted live at checkout for your address.

Plan the unload in advance. Crated, this is a 447 lb pallet and needs a forklift or pallet jack on firm ground, or a trailer collection from the freight terminal. Drivers deliver to the tail of the truck only. Residential delivery is available and carries a fee, shown at checkout. Inspect the crate with the driver and record any damage on the bill of lading before you sign, because a clean signature closes off most later claims.

Schulz collection from Acworth, GA is available. Call, text or chat if you want the regulator question settled or the footprint checked against your plant room first: 866-774-7743.

Warranty

Schulz covers this unit for 1 year. Keep your proof of purchase and note the date it was put into service.

Standard but important: do not dismantle the pump or motor before a claim is raised. An opened machine is normally treated as ineligible however good the diagnosis was. Call us and we will open the claim with Schulz for you.