Cast Air Heavy Duty Shop Tandem Air Compressor — T15324HC1-S
The T15324HC1-S puts two 15 HP motors on a 240-gallon horizontal ASME tank, running the HC1 cast iron pump at 898 RPM. Combined output is 110 CFM at 0 PSI and 90.6 CFM at 175 PSI. At $8,121, this is the 240-gallon version of the HC1 tandem — you get the same pumps as the T15312HC1-S but with double the receiver storage. The larger tank is the right choice when your demand comes in spikes rather than a steady draw: think a blast cabinet running in bursts, a tire shop doing a run of truck tires, or a body shop where several tools fire up at once before dropping back off. The 240-gallon receiver absorbs those spikes so the system pressure stays stable and the pumps do not short-cycle.
120 Gallons vs. 240 Gallons — When Does It Matter?
- 120-gallon tank (T15312HC1-S): Right for shops with moderate, relatively consistent demand. The HC1 pump recovery rate is fast enough to keep the 120-gallon tank charged. Saves floor space and $1,446.
- 240-gallon tank (T15324HC1-S — this unit): Right for shops with intense demand spikes. A fully charged 240-gallon receiver at 175 PSI holds roughly twice the stored air of the 120-gallon version — that buffer is the difference between stable pressure during a peak and dropping to 140 PSI while everyone is working.
- Practical test: Watch your system pressure during your busiest hour. If it drops more than 20–25 PSI below your cut-in point, you need more storage, more CFM, or both. The T15324HC1-S addresses the storage problem while keeping the same pump and motor setup.
Cast Iron Pump Features
- All cast iron construction: Cylinders, heads, crankcase — cast iron throughout for thermal stability and service longevity.
- 898 RPM (HC1 pump): Still dramatically slower than the 1,200–1,800 RPM found in import compressors. Quieter, cooler, longer service intervals than high-speed aluminum-bore equipment.
- Tapered roller bearings: Both crankshaft ends. Handles radial and axial loads at sustained compressor duty better than ball bearings.
- Precision steel connecting rods: Automotive-type rod insert bearings at the crank, needle bearings at the wrist pin.
- Disc and spring valves: Field-serviceable. Easy to inspect and rebuild without pulling the entire pump.
- 4-ring pistons: Better ring seal, higher efficiency, less oil in the discharge stream.
- Centrifugal unloader: Loadless start every cycle. Protects motors and pressure switches from repeated hard starts.
Tank and Controls
- 240-gallon horizontal ASME tank: Powder-coated, channel base for stable installation. Significantly more air storage than the 120-gallon version for the same pump output — the right choice when demand spikes are the problem.
- Two magnetic motor starters — mounted and wired: Factory-installed on both pump sides. Connect to 3-phase service and operate.
- ASME safety valves: Factory-set on both sides.
- Metal belt guards: Fully enclosed on both pump assemblies.
- Copper discharge and unloader tubes: Copper tubing throughout the hot side — more durable than rubber hose at sustained compressor temperatures.
- 1,725 RPM industrial motors: 15% service factor or higher.
Available Factory-Mounted Options
- Low Oil Control (#6304x2M): Auto-shutdown protection on both pumps.
- Hour Meter 230V (#HRM75x2M) or 460V (#HRM460x2M): Independent runtime tracking on each pump.
- Alternator Relay (#ALT230M or #ALT460M): Automatically alternates lead pump each cycle to equalize wear.
- Electronic Auto Drain (#SDV03M): Timed solenoid condensate drain.
- Dual Control (#DC1x2M): Start/stop and throttle modes.
- Intake Noise Silencers (#SA100x4M): Quiets intake on both pumps.
- Belt Tensioner (#254Dx2M): Self-tensioning motor base for consistent belt tension.
- Aftercooler (#BGAC1x2M, 70 CFM rated): Belt-guard-mounted aftercooler.
- All Options Package (#AOC1D): All asterisk options at 10% discount.
What Is in the Box
- Two cast iron two-stage HC1 pump and motor assemblies on a single rigid frame
- 240-gallon horizontal powder-coated ASME tank with channel base
- Two magnetic motor starters, mounted and wired at the factory
- Two ASME safety valves
- Two metal belt guards (fully enclosed)
- Copper discharge and unloader tubes on both sides
- Pressure switch for each pump
Optional accessories are factory-installed at time of order and are not included unless specified at purchase.
Available Configurations — 15 HP Shop Tandem Lineup
- T15312HC1-S: 2×15 HP, 898 RPM, 110 CFM / 90.6 CFM @ 175 PSI, 120-gal — $6,675
- T15312HC2-S: 2×15 HP, 795 RPM, 123.4 CFM / 100.4 CFM @ 175 PSI, 120-gal — $7,639
- T15324HC1-S: 2×15 HP, 898 RPM, 110 CFM / 90.6 CFM @ 175 PSI, 240-gal — $8,121 (this unit)
- T15324HC2-S: 2×15 HP, 795 RPM, 123.4 CFM / 100.4 CFM @ 175 PSI, 240-gal — $9,173
When Does a Shop Need This vs. Stepping Up or Down?
- Step down to 120-gallon (T15312HC1-S): If your demand is steady rather than spikey, and floor space is tight, the 120-gallon unit at $6,675 is $1,446 less and does the same job. The pump output is identical.
- This unit is right when: Your shop has burst demand — multiple tools firing simultaneously, then dropping off — and you want the pressure stability that 240 gallons of storage delivers. Same pumps as the 120-gallon version, more buffer.
- Step up to HC2 (T15324HC2-S): If you need more CFM in addition to more storage, the HC2 pump on the 240-gallon tank gives you 123.4 CFM combined for $9,173. Worth it if the shop is consistently running at or near the HC1's 90.6 CFM capacity at 175 PSI.
Technical Specifications — T15324HC1-S
- Model Number: T15324HC1-S
- Horsepower: 2 × 15 HP (30 HP total)
- Phase: 3-phase
- Pump RPM: 898 (HC1 configuration)
- CFM @ 0 PSI: 110 (combined, both pumps)
- CFM @ 175 PSI: 90.6 (combined, both pumps)
- Tank Capacity: 240 gallons, horizontal
- Tank Type: ASME-certified, powder-coated, channel base
- Motor Speed: 1,725 RPM, 15% service factor
- Pump Type: Two-stage, all cast iron, centrifugal unloader
- Controls: Two magnetic motor starters, mounted and wired
- Discharge Tubing: Copper
- Belt Guard: Metal, fully enclosed
- Price: $8,120.65
Note: Exact LxWxH dimensions and shipping weight for this configuration are not individually published by Castair. Contact us for freight details before ordering.
Why Buy From Air Compressor Factory Direct?
We have specialized in industrial air compressor sales since 2016. We carry Cast Air because their American-built cast iron machines are the right answer for shops that cannot afford downtime. When you buy through us:
- Free shipping to a commercial address with a loading dock or forklift
- Free tech support at 866-217-0063 — we will help you decide between the 120 and 240-gallon options based on your actual demand pattern
- Full Cast Air manufacturer warranty handled directly through us
- Honest upgrade guidance: If the HC1 is the right pump for your load, we will tell you — even if the HC2 costs more.
Call 866-217-0063 for quick answers and help!
