{"product_id":"heavy-duty-shop-tandem-model-no-t20312hc3-s","title":"Heavy Duty Shop Tandem - Model No.: T20312HC3-S","description":"\u003ch2\u003eCast Air Heavy Duty Shop Tandem Air Compressor — T20312HC3-S\u003c\/h2\u003e\n\u003cp\u003eThe T20312HC3-S runs two 20 HP motors on the HC3 cast iron pump at 570 RPM — the slowest, largest pump configuration Cast Air makes for this horsepower range. Combined output is 180 CFM at 0 PSI and 140 CFM at 175 PSI, identical to the HC2 tandem, but achieved at dramatically lower pump speed. The 120-gallon horizontal ASME tank keeps the footprint manageable. At $10,285, you pay a premium over the HC2 configuration ($7,974) for slower RPM, lower operating temperature, reduced noise, and extended service life between major pump maintenance intervals. This is the compressor for shops where the machine runs all day, every day, and long-term cost of ownership matters more than the initial purchase price.\u003c\/p\u003e\n\n\u003ch3\u003eHC2 vs. HC3 — Is the Difference Worth It?\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eHC2 (758 RPM, $7,974):\u003c\/strong\u003e Delivers the same 140 CFM at 175 PSI as the HC3 at a lower purchase price. The right choice for shops with heavy but not continuous demand where pump service intervals of 4,000–6,000 hours are acceptable.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHC3 (570 RPM, $10,285):\u003c\/strong\u003e The HC3 pump is physically larger and runs at 570 RPM — 25% slower than the HC2. Lower RPM means lower operating temperature, less vibration, and longer intervals between valve and ring replacement. For shops running the compressor 8–10+ hours per day, the HC3's longer service life and lower noise level pay back the $2,311 premium over time.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBottom line:\u003c\/strong\u003e If your compressor runs hard all day in a production environment, the HC3 is the correct specification. If your demand is heavy but intermittent, the HC2 is the more economical choice.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eCast Iron Pump Features\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eAll cast iron construction:\u003c\/strong\u003e Cylinders, heads, and crankcase on both pumps. The HC3 is the largest cast iron pump in the Cast Air industrial piston lineup.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e570 RPM (HC3 configuration):\u003c\/strong\u003e The slowest operating speed in the Shop Tandem series. At 570 RPM, the pump is running at a fraction of the speed of import equipment — significantly quieter and generating far less heat per cubic foot of air compressed.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTapered roller bearings:\u003c\/strong\u003e Both ends of each crankshaft. Required for sustained high-load operation at any RPM.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePrecision steel connecting rods:\u003c\/strong\u003e Automotive-type rod insert bearings at the crank, needle bearings at the wrist pin.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDisc and spring valves:\u003c\/strong\u003e Simple to service in the field. At 570 RPM, valve wear is substantially reduced compared to faster pumps running the same duty cycle.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e4-ring pistons:\u003c\/strong\u003e Higher efficiency, less oil carry-over.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCentrifugal unloader:\u003c\/strong\u003e Loadless start every cycle. At 40 HP total, protecting the electrical service from inrush current is not optional — the centrifugal unloader handles it automatically.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eTank and Controls\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e120-gallon horizontal ASME tank:\u003c\/strong\u003e Powder-coated, channel base. At 140 CFM of pump output, the 120-gallon tank charges quickly. Add the HC3's slower recovery time relative to its lower RPM, and the 240-gallon T20324HC3-S is the better choice if your demand has significant spikes.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTwo magnetic motor starters — mounted and wired:\u003c\/strong\u003e Factory-installed on both pump sides. Ready to connect to 3-phase service.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eASME safety valves:\u003c\/strong\u003e Factory-set on both sides.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMetal belt guards:\u003c\/strong\u003e Fully enclosed on both assemblies.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCopper discharge and unloader tubes:\u003c\/strong\u003e Copper throughout the hot side.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e1,725 RPM industrial motors:\u003c\/strong\u003e 15% service factor or higher.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eAvailable Factory-Mounted Options\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eLow Oil Control (#6304x2M):\u003c\/strong\u003e Essential for any production environment where the compressor runs unattended.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHour Meter 230V (#HRM75x2M) or 460V (#HRM460x2M):\u003c\/strong\u003e Track runtime on each pump independently.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAlternator Relay (#ALT230M or #ALT460M):\u003c\/strong\u003e Equalizes wear between both pump sides automatically.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eElectronic Auto Drain (#SDV03M):\u003c\/strong\u003e Timed solenoid condensate drain.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDual Control (#DC2x2M):\u003c\/strong\u003e Start\/stop and throttle control modes. Standard on HC3 configurations.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIntake Noise Silencers (#SA100x4M):\u003c\/strong\u003e The HC3 is already quieter at 570 RPM — silencers reduce intake noise further if the compressor room is near the work area.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAftercooler (#BGAC1x2M, 70 CFM rated):\u003c\/strong\u003e Belt-guard-mounted aftercooler on both pump sides.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAll Options Package (#AOC3D):\u003c\/strong\u003e All asterisk options at 10% off. Note: Dual control is standard on HC3 units; cannot combine intake silencers and dual control on HC3.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhat Is in the Box\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eTwo cast iron two-stage HC3 pump and motor assemblies (20 HP each) on a single rigid frame\u003c\/li\u003e\n\u003cli\u003e120-gallon horizontal powder-coated ASME tank with channel base\u003c\/li\u003e\n\u003cli\u003eTwo magnetic motor starters, mounted and wired at the factory\u003c\/li\u003e\n\u003cli\u003eTwo ASME safety valves\u003c\/li\u003e\n\u003cli\u003eTwo metal belt guards (fully enclosed)\u003c\/li\u003e\n\u003cli\u003eCopper discharge and unloader tubes on both sides\u003c\/li\u003e\n\u003cli\u003ePressure switch for each pump\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cem\u003eOptional accessories are factory-installed at time of order and are not included unless specified at purchase.\u003c\/em\u003e\u003c\/p\u003e\n\n\u003ch3\u003eAvailable Configurations — 20 HP Shop Tandem Lineup\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eT20312HC2-S:\u003c\/strong\u003e 2×20 HP, 758 RPM, 180 CFM \/ 140 CFM @ 175 PSI, 120-gal — $7,974\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eT20312HC3-S:\u003c\/strong\u003e 2×20 HP, 570 RPM, 180 CFM \/ 140 CFM @ 175 PSI, 120-gal — $10,285 (this unit)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eT20324HC2-S:\u003c\/strong\u003e 2×20 HP, 758 RPM, 180 CFM \/ 140 CFM @ 175 PSI, 240-gal — $9,460\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eT20324HC3-S:\u003c\/strong\u003e 2×20 HP, 570 RPM, 180 CFM \/ 140 CFM @ 175 PSI, 240-gal — $11,610\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhen Does a Shop Need This vs. Stepping Up or Down?\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eStep down to HC2:\u003c\/strong\u003e If your compressor runs 6 hours per day or less with recovery time, the T20312HC2-S at $7,974 delivers identical CFM output for $2,311 less. Spend that savings on a good aftercooler and auto drain package.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThis unit is right when:\u003c\/strong\u003e You run an automotive production line, a high-volume collision repair shop, or any operation where the compressor cycles continuously 8–12 hours per day. The HC3 pump's 570 RPM operating speed pays back its premium in lower maintenance costs and longer service life at those duty levels.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eConsider 240-gallon tank:\u003c\/strong\u003e For production environments with burst demand, the T20324HC3-S adds 120 gallons of receiver storage for $1,325 more — worth it if pressure stability during peak demand is a priority.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eTechnical Specifications — T20312HC3-S\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eModel Number:\u003c\/strong\u003e T20312HC3-S\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHorsepower:\u003c\/strong\u003e 2 × 20 HP (40 HP total)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePhase:\u003c\/strong\u003e 3-phase\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePump RPM:\u003c\/strong\u003e 570 (HC3 configuration)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCFM @ 0 PSI:\u003c\/strong\u003e 180 (combined, both pumps)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCFM @ 175 PSI:\u003c\/strong\u003e 140 (combined, both pumps)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTank Capacity:\u003c\/strong\u003e 120 gallons, horizontal\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTank Type:\u003c\/strong\u003e ASME-certified, powder-coated, channel base\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMotor Speed:\u003c\/strong\u003e 1,725 RPM, 15% service factor\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePump Type:\u003c\/strong\u003e Two-stage, all cast iron, centrifugal unloader\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eControls:\u003c\/strong\u003e Two magnetic motor starters, mounted and wired; Dual Control standard\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDischarge Tubing:\u003c\/strong\u003e Copper\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBelt Guard:\u003c\/strong\u003e Metal, fully enclosed\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePrice:\u003c\/strong\u003e $10,285.35\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cem\u003eNote: Exact LxWxH dimensions and shipping weight for this configuration are not individually published by Castair. Contact us for freight details before ordering.\u003c\/em\u003e\u003c\/p\u003e\n\n\u003ch3\u003eWhy Buy From Air Compressor Factory Direct?\u003c\/h3\u003e\n\u003cp\u003eWe have specialized in industrial air compressor sales since 2016. The HC2 vs. HC3 decision is one of the most common questions we field — and the answer genuinely depends on your specific duty cycle, not just the price. We will tell you which configuration actually fits your operation.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eFree shipping\u003c\/strong\u003e to a commercial address with a loading dock or forklift\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFree tech support at 866-217-0063\u003c\/strong\u003e — we will help you assess whether HC2 or HC3 is right for your shop's actual duty cycle\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFull Cast Air manufacturer warranty\u003c\/strong\u003e — handled directly through us\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHonest upgrade guidance:\u003c\/strong\u003e We carry the full Cast Air lineup. If a different configuration fits better, we will tell you.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eCall 866-217-0063 for quick answers and help!\u003c\/strong\u003e\u003c\/p\u003e","brand":"Cast Air","offers":[{"title":"Default Title","offer_id":53342605607125,"sku":"T20312HC3-S","price":10285.35,"currency_code":"USD","in_stock":true}],"url":"https:\/\/aircompressorfactorydirect.com\/products\/heavy-duty-shop-tandem-model-no-t20312hc3-s","provider":"Air Compressor Factory Direct","version":"1.0","type":"link"}