{"product_id":"castair-25hp-industrial-series-reciprocating-air-compressor-240-gallon-horizontal-i25324hc4z-s","title":"Castair 25HP Industrial Series Reciprocating Air Compressor 240 Gallon Horizontal I25324HC4Z-S","description":"\u003ch2\u003eCastair I25324HC4Z-S: 25HP 3-Phase Industrial Reciprocating Air Compressor — 240 Gallon Horizontal with Mounted Starter\u003c\/h2\u003e\n\n\u003cp\u003eThe Castair I25324HC4Z-S is a 25-horsepower, 3-phase, 240-gallon horizontal industrial reciprocating air compressor priced at 2,775. This is the maximum-storage configuration in Castair's 25HP lineup — the same C4 cast iron pump as the 120-gallon model, but with double the tank capacity to handle high-demand shops and production environments where air supply consistency is critical.\u003c\/p\u003e\n\n\u003cp\u003eAt 25HP and 710 RPM, the C4 pump delivers 90 CFM at 175 PSI. That output supports 6-8 simultaneous technician workstations running standard pneumatic tools, or a large body shop with an active spray booth and general shop air demand running concurrently. The 240-gallon tank stores enough compressed air to buffer significant demand spikes — keeping system pressure stable even when multiple high-CFM tools activate simultaneously.\u003c\/p\u003e\n\n\u003cp\u003eThe Z designation means a factory-mounted magnetic motor starter is included. At 25HP on 3-phase, this is not optional for a code-compliant installation — having it factory-mounted by Castair means the motor and starter are properly matched and wired before the unit leaves the factory.\u003c\/p\u003e\n\n\u003ch2\u003eC4 Pump — Engineering Details\u003c\/h2\u003e\n\n\u003ch3\u003eConstruction\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003ePump designation:\u003c\/strong\u003e C4 — Two-stage, V4 cylinder configuration\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRated HP range:\u003c\/strong\u003e 15-25HP\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePump RPM at 25HP:\u003c\/strong\u003e 710\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eConstruction:\u003c\/strong\u003e 100% cast iron — cylinders, heads, valve plates, crankcase\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFlywheel:\u003c\/strong\u003e 13-3B\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOil capacity:\u003c\/strong\u003e 1 gallon\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBearings:\u003c\/strong\u003e Tapered roller bearings at both crankshaft ends for superior support and reduced friction\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eConnecting rods:\u003c\/strong\u003e Precision steel with automotive-type rod insert bearings at crankshaft and wrist pin\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eValves:\u003c\/strong\u003e Disc and spring — field-replaceable, no specialized tooling needed\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePistons:\u003c\/strong\u003e 4-ring for high efficiency and minimal oil carry-over\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUnloader:\u003c\/strong\u003e Centrifugal — every startup is loadless, protecting the motor\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eTank and Frame\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eTank capacity:\u003c\/strong\u003e 240 gallons, horizontal\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDimensions:\u003c\/strong\u003e 90 x 39 x 70 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTank construction:\u003c\/strong\u003e Powder-coated ASME-rated steel with channel saddle frame\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSafety valve:\u003c\/strong\u003e ASME-rated, factory installed\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBelt guard:\u003c\/strong\u003e Totally enclosed metal\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDischarge lines:\u003c\/strong\u003e Copper tubing or stainless braided flex line\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eMotor and Electrical\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eHorsepower:\u003c\/strong\u003e 25HP\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePhase:\u003c\/strong\u003e 3-phase\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMotor speed:\u003c\/strong\u003e 1725 RPM industrial\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eService factor:\u003c\/strong\u003e 15% minimum\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMotor starter:\u003c\/strong\u003e Factory-mounted magnetic motor starter (Z designation)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMax working pressure:\u003c\/strong\u003e 175 PSI\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003ePerformance Specifications\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMotor output:\u003c\/strong\u003e 25 HP\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eElectrical:\u003c\/strong\u003e 3-phase with factory-mounted magnetic starter\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTank capacity:\u003c\/strong\u003e 240 gallons, horizontal\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePump:\u003c\/strong\u003e C4 (Two-stage, V4)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePump RPM:\u003c\/strong\u003e 710\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFree air delivery (0 PSI):\u003c\/strong\u003e 109 CFM\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDelivery at 175 PSI:\u003c\/strong\u003e 90 CFM\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMax pressure:\u003c\/strong\u003e 175 PSI\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDimensions (LxWxH):\u003c\/strong\u003e 90 x 39 x 70 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 1,725 lbs\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePrice:\u003c\/strong\u003e 2,775\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eWhat's in the Box\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eCastair I25324HC4Z-S compressor — fully assembled on 240-gallon horizontal tank\u003c\/li\u003e\n\u003cli\u003eFactory-mounted magnetic motor starter (Z designation)\u003c\/li\u003e\n\u003cli\u003eASME safety valve (factory installed)\u003c\/li\u003e\n\u003cli\u003ePressure switch with unloader\u003c\/li\u003e\n\u003cli\u003eTotally enclosed metal belt guard\u003c\/li\u003e\n\u003cli\u003eCopper discharge and unloader tubing (or stainless braided flex line)\u003c\/li\u003e\n\u003cli\u003eOwner's documentation\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cem\u003eAftercooler available as factory option (BGAC3M — for 20HP and up). Electrical connection to 3-phase service by licensed electrician. Freight delivery requires loading dock or forklift at destination.\u003c\/em\u003e\u003c\/p\u003e\n\n\u003ch2\u003eFull Lineup Comparison — 20HP through 30HP on C4 Platform\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eI20324HC4Z-S:\u003c\/strong\u003e 20HP, 3-phase, 240gal Horizontal, C4 pump, 519 RPM, 72 CFM @ 175 PSI, 1,700 lbs — 2,542\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eI25324HC4Z-S (this unit):\u003c\/strong\u003e 25HP, 3-phase, 240gal Horizontal, C4 pump, 710 RPM, 90 CFM @ 175 PSI, 1,725 lbs — 2,775\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eI30324HC4Z-S:\u003c\/strong\u003e 30HP, 3-phase, 240gal Horizontal, C4 pump, 794 RPM, 105 CFM @ 175 PSI, 1,750 lbs\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eAt the 240-gallon level, the price differences between the 20, 25, and 30HP configurations are relatively modest — the major cost is the tank and pump assembly. If you are within 00 of the next HP tier, consider what your peak demand looks like in 3-5 years as your shop grows. Stepping up one tier now costs less than replacing the motor or the whole unit later.\u003c\/p\u003e\n\n\u003ch2\u003eWhen Does a Shop Need This vs. Stepping Up or Down?\u003c\/h2\u003e\n\n\u003ch3\u003eI25324HC4Z-S is right when:\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eYou need 80-90 CFM at 175 PSI continuously — large body shop, production line, multi-bay truck service facility\u003c\/li\u003e\n\u003cli\u003eYour demand includes high-volume spikes (spray booth + general shop air simultaneously) and you need the 240-gallon buffer to maintain pressure\u003c\/li\u003e\n\u003cli\u003eYou have 3-phase service and a factory-mounted starter simplifies your installation\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eStep down to the 120-gallon (I25312HC4Z-S) if:\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eYour installation space limits you to the smaller footprint and your demand is steady enough that 120 gallons provides adequate pressure recovery\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eStep down to 20HP if:\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eYour actual running demand is below 72 CFM at pressure — running a 25HP compressor lightly wastes electricity and can cause short-cycling issues\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eStep up to 30HP (I30324HC4Z-S) if:\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eYour continuous demand is above 90 CFM — the 30HP delivers 105 CFM at 175 PSI from the same C4 platform at 794 RPM\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eWhy Buy From Air Compressor Factory Direct?\u003c\/h2\u003e\n\u003cp\u003eSince 2016, we have specialized in industrial air compressors and shop equipment. A 25HP, 240-gallon unit at this price point is a capital equipment purchase — we treat it accordingly. Before you order, we can review your shop layout, electrical service specs, and CFM requirements to confirm this is the right configuration. After your purchase, we provide ongoing tech support at no charge.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eFree shipping\u003c\/strong\u003e to commercial addresses in the lower 48 states (freight — loading dock or forklift required)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFree tech support\u003c\/strong\u003e at 866-217-0063\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eFull Castair manufacturer warranty\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHonest configuration guidance\u003c\/strong\u003e — we will tell you if the 20HP or 30HP is the better fit\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAuthorized dealer\u003c\/strong\u003e with direct Castair factory support\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eCall 866-217-0063 for quick answers and help!\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cdiv class=\"product-faq\"\u003e\n\u003ch2\u003eFrequently Asked Questions\u003c\/h2\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003ch3\u003eWhat is the duty cycle on the I25324HC4Z-S, and can it run continuously in a production environment?\u003c\/h3\u003e\n\u003cp\u003eThe Cast Air I25324HC4Z-S is rated for continuous-duty operation — the 25 HP motor and all-cast-iron pump are built to run production shifts without thermal shutdown concerns you'd see with aluminum-cylinder compressors. The 240-gallon horizontal tank gives you enough stored volume that the pump isn't short-cycling constantly, which is where most compressors accumulate wear. For high-demand shops running air tools, spray booths, or plasma cutters back-to-back, this unit is sized to keep up without babysitting.\u003c\/p\u003e\n\u003c\/div\u003e\n\n\u003cdiv class=\"faq-item\"\u003e\n\u003ch3\u003eWhat type of oil does the Cast Air I25324HC4Z-S require, and how often does it need to be changed?\u003c\/h3\u003e\n\u003cp\u003eCast Air recommends a non-detergent compressor oil — SAE 30 weight for ambient temps above 40°F, SAE 20 below that. Change interval is every 500 hours under normal conditions; bump that to 250 hours if you're running in a dusty environment or the intake air quality is poor. Because the pump is full cast iron throughout, it's not as sensitive to oil breakdown as an aluminum-cylinder unit, but sticking to the interval matters for ring seal and bearing life on a pump you want running 10–15 years.\u003c\/p\u003e\n\u003c\/div\u003e\n\n\u003cdiv class=\"faq-item\"\u003e\n\u003ch3\u003eWhy does the I25324HC4Z-S require 3-phase power instead of single-phase — can I run it on 240V single-phase?\u003c\/h3\u003e\n\u003cp\u003eNo — at 25 HP, single-phase power is not a practical option. Starting current on a 25 HP single-phase motor would require service entrance capacity most shops simply don't have, and the motor itself would be significantly larger and less efficient. Three-phase power gives you smoother torque delivery, lower amperage draw at startup, and longer motor life. If your shop is on single-phase only, the realistic ceiling is around 10–15 HP; anything above that, you're looking at a phase converter or getting 3-phase service brought in — which, for a machine at this output level, is the right call.\u003c\/p\u003e\n\u003c\/div\u003e\n\n\u003cdiv class=\"faq-item\"\u003e\n\u003ch3\u003eIs a 240-gallon tank actually necessary at 25 HP, or is the tank just marketing on this model?\u003c\/h3\u003e\n\u003cp\u003eTank size matters for two separate reasons: pressure recovery lag and pump duty cycle. At 25 HP, the pump is producing plenty of CFM, but high-draw tools like 1-inch impact wrenches, DA sanders running in parallel, or intermittent blast cabinet use will pull pressure down fast if the tank is undersized. The 240-gallon vessel on the I25324HC4Z-S means you have a meaningful buffer — the pump runs longer charging cycles and fewer total cycles per shift. For a shop running 4–8 air drops simultaneously, that tank volume is the difference between stable line pressure and hunting for pressure mid-task.\u003c\/p\u003e\n\u003c\/div\u003e\n\n\u003cdiv class=\"faq-item\"\u003e\n\u003ch3\u003eWhat size shop is the Cast Air I25324HC4Z-S actually suited for, and is it overkill for a smaller operation?\u003c\/h3\u003e\n\u003cp\u003eThis unit is built for serious commercial and light industrial environments — think a 6–10 bay auto repair shop, a medium production floor, a fabrication shop with multiple welders and grinders running air, or a body shop with multiple spray booths. At 25 HP and 240 gallons, it's not cost-effective for a 1–2 bay garage; you'd be buying more compressor than you'll ever use. If you're unsure whether this model is the right match for your CFM demand and shop layout, call us at \u003ca href=\"tel:866-217-0063\"\u003e866-217-0063\u003c\/a\u003e — as an authorized Cast Air dealer, we can work through your actual air demand numbers and point you to the right unit rather than oversell you.\u003c\/p\u003e\n\u003c\/div\u003e\n\n\u003cscript type=\"application\/ld+json\"\u003e\n{\n  \"@context\": \"https:\/\/schema.org\",\n  \"@type\": \"FAQPage\",\n  \"mainEntity\": [\n    {\n      \"@type\": \"Question\",\n      \"name\": \"What is the duty cycle on the I25324HC4Z-S, and can it run continuously in a production environment?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"The Cast Air I25324HC4Z-S is rated for continuous-duty operation — the 25 HP motor and all-cast-iron pump are built to run production shifts without thermal shutdown concerns you'd see with aluminum-cylinder compressors. The 240-gallon horizontal tank gives you enough stored volume that the pump isn't short-cycling constantly, which is where most compressors accumulate wear. For high-demand shops running air tools, spray booths, or plasma cutters back-to-back, this unit is sized to keep up without babysitting.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"What type of oil does the Cast Air I25324HC4Z-S require, and how often does it need to be changed?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Cast Air recommends a non-detergent compressor oil — SAE 30 weight for ambient temps above 40°F, SAE 20 below that. Change interval is every 500 hours under normal conditions; bump that to 250 hours if you're running in a dusty environment or the intake air quality is poor. Because the pump is full cast iron throughout, it's not as sensitive to oil breakdown as an aluminum-cylinder unit, but sticking to the interval matters for ring seal and bearing life on a pump you want running 10–15 years.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Why does the I25324HC4Z-S require 3-phase power instead of single-phase — can I run it on 240V single-phase?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"No — at 25 HP, single-phase power is not a practical option. Starting current on a 25 HP single-phase motor would require service entrance capacity most shops simply don't have, and the motor itself would be significantly larger and less efficient. Three-phase power gives you smoother torque delivery, lower amperage draw at startup, and longer motor life. If your shop is on single-phase only, the realistic ceiling is around 10–15 HP; anything above that, you're looking at a phase converter or getting 3-phase service brought in — which, for a machine at this output level, is the right call.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Is a 240-gallon tank actually necessary at 25 HP, or is the tank just marketing on this model?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Tank size matters for two separate reasons: pressure recovery lag and pump duty cycle. At 25 HP, the pump is producing plenty of CFM, but high-draw tools like 1-inch impact wrenches, DA sanders running in parallel, or intermittent blast cabinet use will pull pressure down fast if the tank is undersized. The 240-gallon vessel on the I25324HC4Z-S means you have a meaningful buffer — the pump runs longer charging cycles and fewer total cycles per shift. For a shop running 4–8 air drops simultaneously, that tank volume is the difference between stable line pressure and hunting for pressure mid-task.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"What size shop is the Cast Air I25324HC4Z-S actually suited for, and is it overkill for a smaller operation?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"This unit is built for serious commercial and light industrial environments — think a 6–10 bay auto repair shop, a medium production floor, a fabrication shop with multiple welders and grinders running air, or a body shop with multiple spray booths. At 25 HP and 240 gallons, it's not cost-effective for a 1–2 bay garage; you'd be buying more compressor than you'll ever use. If you're unsure whether this model is the right match for your CFM demand and shop layout, call us at 866-217-0063 — as an authorized Cast Air dealer, we can work through your actual air demand numbers and point you to the right unit rather than oversell you.\"\n      }\n    }\n  ]\n}\n\u003c\/script\u003e\n\u003c\/div\u003e","brand":"Cast Air","offers":[{"title":"Default Title","offer_id":53342561730773,"sku":"I25324HC4Z-S","price":22746.98,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0622\/8466\/0949\/files\/I30324HC4Z-S_851e2ca2-4ce7-4a64-93c6-c8f45859315c.jpg?v=1772652709","url":"https:\/\/aircompressorfactorydirect.com\/products\/castair-25hp-industrial-series-reciprocating-air-compressor-240-gallon-horizontal-i25324hc4z-s","provider":"Air Compressor Factory Direct","version":"1.0","type":"link"}