Castair 5HP 1-Phase Rotary Screw Air Compressor 80 Gallon Vertical — R518VP75
The Castair R518VP75 is a 5-horsepower, single-phase, 80-gallon vertical rotary screw air compressor delivering 20 CFM at 100 PSI. It weighs 480 pounds and measures 34 inches wide by 26 inches deep by 70 inches tall. The vertical tank configuration takes up significantly less floor space than the horizontal version — 34"×26" versus 64"×32" — making this the better choice when you need to preserve floor space and ceiling height isn't a constraint. Single-phase 230V power means no 3-phase service required, which makes this unit accessible to shops that have standard commercial power.
Vertical Tank — Floor Space Efficiency
- Small footprint: 34"×26" base takes up less than 6 square feet of floor space. The horizontal version (R518HP75) requires a 64"×32" area — nearly double the floor length.
- 70-inch height: Taller than the horizontal unit's 44". Measure your ceiling clearance before ordering. Standard 8-foot ceilings provide adequate clearance; lower ceilings may dictate the horizontal configuration.
- Wall-adjacent mounting: The vertical tank's narrow profile fits neatly against a wall. The center of gravity is higher than horizontal, so ensure the floor is level and the unit has adequate stability.
- Same output as horizontal: Both the R518VP75 and R518HP75 deliver 20 CFM at 100 PSI. The only practical difference is the footprint and height — the compressor and motor are the same.
20 CFM at 100 PSI in a Real Shop
- 1/2-inch impact wrench: 4-8 CFM — two running simultaneously with room to spare
- 3/8-inch air ratchet: 4-6 CFM — comfortable for multiple tools at once
- DA sander: 12-20 CFM — one sander at a time at the full output rating
- HVLP spray gun: 9-14 CFM — painting with one gun is fine; pressure stays stable
- 1-inch impact wrench: 10-25 CFM — works for intermittent heavy use; continuous heavy-duty use should step up to 7.5HP
- Blow guns, tire inflation, air chisels: All well within capacity
100% Duty Cycle — The Real Difference from Piston
- Never waiting for pressure: Rotary screw compressors deliver continuous output. No waiting for the tank to recharge after running it down with a heavy tool.
- No heat buildup shutdown: Piston compressors at 5HP typically need to cool down after sustained use. This rotary screw is designed to run continuously — you can run it all day without rest periods.
- Stable pressure at the tool: Output pressure stays consistent. Piston units cycle between cut-in and cut-out, which causes pressure to drop at the tool during high demand.
Castair Build Quality
- All cast iron construction: Not aluminum. Cast iron handles shop heat cycles, vibration, and long-term wear better than aluminum castings.
- Industrial 1725 RPM motor, full 15% service factor: Designed for commercial use. The service factor means it handles occasional peak loads without damage.
- Single solenoid air end control: Simple and field-repairable. No proprietary electronics or diagnostic tools required. One solenoid, one function.
- Analog pressure and temperature gauges standard: Read them at a glance. No menus, no displays to interpret.
- High pressure and dual high temperature shutdown standard: The unit shuts itself down before damage occurs. Both protections are standard, not options.
- Factory-filled with Cast-Lube synthetic oil: 4,000-hour or one-year interval. Ships ready to run — no break-in oil swap needed.
- Built-in air/oil separator with spin-on filter: Keeps oil out of the air supply. Standard spin-on replacement, not proprietary.
- Off-shelf V-belts with adjustable tensioner: Available at any industrial supply. No factory ordering for basic maintenance consumables.
- Air/oil lines in copper pipe: Handles heat, handles vibration, standard plumbing fittings.
- Air-cooled aftercooler/oil cooler standard: Removable for cleaning. Controls oil temperature and reduces moisture in the compressed air.
- Hour meter standard: Know when maintenance is due based on actual run hours.
- 10-minute auto shutdown timer: No air demand for 10 minutes = unit shuts off automatically. Practical electricity savings in a real shop.
- ASME-rated 80-gallon tank: Code-compliant. Required for most commercial insurance and inspection.
- Pre-wired magnetic starter: Just connect incoming 230V single-phase power.
- Pressure options: 135 PSI standard, 150 or 175 PSI available.
- 2-year warranty on air end, electric motor, and tank
- Made in Spicer, Minnesota
Available Configurations — Castair 5HP Rotary Screw
- R518VP75 (this unit): 5HP, 1-Phase, 80 Gal Vertical — 20 CFM @ 100 PSI — 34×26×70" — 480 lbs
- R518HP75: 5HP, 1-Phase, 80 Gal Horizontal — 20 CFM @ 100 PSI — 64×32×44" — 480 lbs
- R518VG11: 5HP, 1-Phase, 80 Gal Vertical with G11 air end
- R518HG11: 5HP, 1-Phase, 80 Gal Horizontal with G11 air end
- 3-Phase 230V Vertical: R538VP75 — 20 CFM @ 100 PSI — 34×26×70" — 470 lbs
- 3-Phase 460V Vertical: R538VP75-460
- Step up to 7.5HP Vertical: R718VP75 — 31 CFM @ 100 PSI — 34×26×70" — 555 lbs
When Does a Shop Need This vs. Stepping Up or Down?
- Right for: 1-2 bay shop with single-phase power, floor space is at a premium, ceiling height is adequate. One primary tech running air tools through a full shift.
- Choose horizontal (R518HP75) if: Ceiling clearance is limited. Same output, lower profile, more floor footprint.
- Step up to 7.5HP (R718VP75) if: Two or more techs regularly run air tools simultaneously. 31 CFM @ 100 PSI handles multiple tools without pressure drop.
- Choose 3-phase if: Your facility has 3-phase service. The 3-phase motors start cleaner, draw less amperage per leg, and have simpler motor construction.
- Consider piston if: Truly intermittent light use — a tire chuck and blow gun once in a while. Don't put a rotary screw where a piston is adequate. Rotary screw earns its cost at sustained demand levels.
Technical Specifications
- Model: R518VP75
- Horsepower: 5 HP
- Phase: 1-Phase
- Voltage: 230V single-phase
- Tank: 80 gallon, vertical, ASME-rated
- CFM @ 100 PSI: 20
- Dimensions (L×W×H): 34" × 26" × 70"
- Weight: 480 lbs
- Compressor Type: Rotary screw (air end: P75)
- Duty Cycle: 100%
- Standard Pressure: 135 PSI (150 or 175 PSI optional)
- Motor Speed: 1725 RPM industrial, full 15% service factor
- Drive: Belt drive, off-shelf V-belts with adjustable tensioner
- Lubrication: Oil-injected, Cast-Lube synthetic, 4,000-hour/1-year interval
- Controls: Single solenoid, pre-wired magnetic starter, analog gauges, hour meter, 10-minute auto shutdown
- Shutdowns: High pressure, dual high temperature (standard)
- Warranty: 2-year on air end, electric motor, and tank
- Manufacturer: Castair, Inc. (Spicer, Minnesota)
What's in the Box
- Castair rotary screw compressor assembly mounted on 80-gallon vertical ASME tank
- Pre-wired magnetic starter and controls (connect 230V single-phase incoming power)
- Air/oil separator with spin-on filter
- Air-cooled aftercooler/oil cooler
- Hour meter
- Pre-filled with Cast-Lube synthetic oil
- Analog pressure and temperature gauges installed
Recommended Accessories
- Preventative Maintenance Kit MKP75: 2 air filters, 4 oil filters, 1 separator filter, 5 gallons Cast-Lube synthetic oil — 10% savings over individual purchase
- Auto Tank Drain SDV03M: Automatic condensate purging — essential for humid climates or high-cycle applications
- Vibration Pads VP1004: 4"×4"×1" set of 4 — reduces vibration transmitted to concrete floor
- Ball Valve BV75 (3/4"): Full-flow outlet shutoff
- Metal Flex Hose VA075 (3/4" NPT × 18"): Isolates tank from hard plumbing, absorbs vibration
Why Buy From Air Compressor Factory Direct?
- Castair specialist: We carry the full lineup and know every model, configuration, and accessory in the catalog
- Free shipping on qualifying orders
- Free technical support: Call 866-217-0063 — talk to someone who understands rotary screw systems and shop air requirements
- Full manufacturer warranty honored and supported
- Honest sizing advice: Tell us your shop size, number of bays, and tools — we'll confirm whether 5HP is right or whether you need more
Call 866-217-0063 for quick answers and help!
