The Castair I738VC2-S is a 7.5 HP, 3-phase industrial air compressor on an 80-gallon vertical ASME tank with the C2 pump and a factory-mounted magnetic motor starter. The C2 pump runs at 585 RPM and delivers 35.0 CFM at 0 PSI and 28.1 CFM at 175 PSI — the highest CFM output in the 7.5HP 80-gallon 3-phase vertical lineup. Tank dimensions are 40x24x74 inches (slightly wider than the C1 vertical to accommodate the larger pump), and shipping weight is 730 lbs. This is the unit for a shop that needs maximum airflow in the 7.5HP vertical tank format.
Why the C2 Pump at 585 RPM
The C2 pump's V4 configuration and lower shaft speed produce two advantages over the C1 at 895 RPM:
- More CFM: 28.1 vs. 24.8 at 175 PSI — meaningful difference when running spray guns, DA polishers, or three air tools simultaneously
- Lower operating temperature: 585 RPM generates less heat per hour than 895 RPM — over the life of the pump, that translates to less wear and longer service intervals
Pump Features — Cast Iron C2 Two-Stage V4
- All cast iron V4 cylinder configuration: Four cylinders in a V arrangement — higher displacement than the C1, producing more CFM at lower RPM
- Slow 585 RPM operation: Lower shaft speed means less heat and less wear than faster-turning pump designs
- Tapered roller bearings at both crankshaft ends: Superior support for the larger pump's loads under belt drive and two-stage compression
- Precision steel connecting rods: Automotive-type insert bearings at crankshaft, needle bearings at wrist pin
- Disc and spring valves: Field-serviceable, reliable under continuous duty cycling
- 4-ring pistons: Less oil carry-over into the discharge air
- Centrifugal unloader: No-load start every time, protecting motor and pump
Tank and Frame Features
- 80-gallon vertical ASME-rated tank: Powder coated, four-leg base for stable floor installation — takes less floor space than a horizontal of the same capacity
- ASME safety valve: Factory installed, rated for working pressure
- Metal belt guard: Fully enclosed — not a plastic clip-on
- Copper discharge and unloader tube: Better heat dissipation than rubber or plastic lines
Motor and Electrical
- 1,725 RPM heavy-duty industrial motor: Full 15% service factor or higher — continuous duty rated
- Factory-mounted magnetic motor starter: 3-phase overload protection installed and wired at the factory — ready to connect to your electrical panel
- 3-phase operation: Smooth starts, lower peak current draw, longer motor life vs. single-phase
What's in the Box
- Castair I738VC2-S compressor assembly (C2 pump, motor, 80-gal vertical tank, belt drive, belt guard)
- Factory-mounted magnetic motor starter (3-phase, sized for 7.5HP)
- ASME safety valve (installed)
- Copper discharge and unloader tube (installed)
- Pressure switch (installed)
Available Configurations — 7.5HP 3-Phase Industrial Lineup
- I738HC1-S: 7.5HP, 3-phase, 80-gal horizontal, C1 pump, 895 RPM, 24.8 CFM@175PSI, 64x20x48 in., 625 lbs, magnetic starter included
- I738HC1: Same as above without factory-mounted magnetic starter
- I738HC2-S: 7.5HP, 3-phase, 80-gal horizontal, C2 pump, 585 RPM, 28.1 CFM@175PSI, 64x20x46 in., 730 lbs, magnetic starter included
- I738HC2: Same as above without factory-mounted magnetic starter
- I738VC1-S: 7.5HP, 3-phase, 80-gal vertical, C1 pump, 895 RPM, 24.8 CFM@175PSI, 32x24x74 in., 625 lbs, magnetic starter included
- I738VC1: Same as above without factory-mounted magnetic starter
- I738VC2-S: 7.5HP, 3-phase, 80-gal vertical, C2 pump, 585 RPM, 28.1 CFM@175PSI, 40x24x74 in., 730 lbs, magnetic starter included
- I738VC2: Same as above without factory-mounted magnetic starter
- I7312HC2-S: 7.5HP, 3-phase, 120-gal horizontal, C2 pump — maximum reserve for high-demand shops
When Does a Shop Need This vs. Stepping Up or Down
The I738VC2-S is right for your shop if: You have 3-phase power, need the C2 pump's higher CFM output (28.1 CFM@175PSI), and the vertical tank configuration works better for your floor layout. At 40x24x74 inches, it gives you the C2 pump's extra airflow in a tighter floor footprint than the equivalent horizontal. The C2 runs at 585 RPM — quieter and cooler than the C1 at 895 RPM.
Choose horizontal (I738HC2-S) instead if ceiling height is the constraint — the horizontal tank at 46 inches tall clears low ceilings that the 74-inch vertical won't fit under.
Step down to I738VC1-S if 24.8 CFM at 175 PSI covers your shop's sustained demand — the C1 pump is simpler and lighter, and the CFM difference (3.3 CFM at 175 PSI) only matters for higher-demand tool combinations.
Technical Specifications
- Model: I738VC2-S
- Horsepower: 7.5 HP
- Phase: 3-phase
- Tank Capacity: 80 gallons
- Tank Type: Vertical, ASME-rated, powder coated
- Tank Dimensions: 40 x 24 x 74 in. (L x W x H)
- Shipping Weight: 730 lbs
- Pump Model: C2 (two-stage, cast iron, V4)
- Pump RPM: 585
- CFM @ 0 PSI: 35.0
- CFM @ 175 PSI: 28.1
- Max Working Pressure: 175 PSI
- Motor Speed: 1,725 RPM
- Starter: Factory-mounted magnetic motor starter included
- Magnetic Starter (208/230V): S72 with B36 heaters
- Magnetic Starter (460V): S74 with B22 heaters
- Discharge Tube: Copper
- Belt Guard: Metal, fully enclosed
Why Buy From Air Compressor Factory Direct?
We specialize in industrial and commercial air compressors and have been at it since 2016. When you call, you're talking to someone who knows the Castair lineup, can tell you whether the C1 or C2 pump fits your shop's CFM requirements, and can help you decide between horizontal and vertical tank configurations for your space. Free shipping, free technical support at 866-217-0063, full Castair manufacturer warranty. Call us before you buy if you have questions about which configuration is right for your shop.
Call 866-217-0063 for quick answers and help!
