Castair 8P150D — 8 Gallon Direct Drive Portable Air Receiver Tank, 150 PSI
The Castair 8P150D is an 8-gallon portable air receiver tank built for direct drive compressor assemblies. This is the base tank for contractor-style portable units — the kind that rides on a job site, fits in a truck bed, and gets used hard. Cast Air manufactures this tank in Minnesota using proper steel construction with pressure-rated fittings, and it is sized and drilled specifically for direct drive motor-pump mounting.
If you are building a direct drive portable compressor from the pump up, or replacing a failed tank on an existing unit, the 8P150D is the starting point. The top plate dimensions are drilled for DD mounting — not belt drive. Get this right before you order.
Tank Specifications
- Part Number: 8P150D
- Capacity: 8 gallons
- Dimensions: 10" diameter x 24" length
- Top Plate: 6" x 7" — sized for direct drive (DD) motor-pump mounting
- Maximum Working Pressure: 150 PSI
- Weight: 30 lbs
- Configuration: Portable (horizontal orientation, designed for wheeled cart or frame)
- ASME Code: Non-code (appropriate for portable compressor units at this pressure and volume)
Direct Drive vs. Belt Drive — Why the Top Plate Matters
The top plate is the drilled mounting surface on top of the tank where the motor-pump assembly bolts down. The 8P150D has a 6x7" top plate — compact because on a direct drive unit, the motor couples directly to the pump crank. There is no belt, no pulley, and no extended motor offset. The footprint is smaller and the whole assembly sits tighter.
The belt drive version (8P150B) uses a 6x16" top plate to accommodate the longer motor-and-pulley arrangement. If you order the wrong tank, the mounting holes will not line up. Confirm your drive type before ordering.
What the 8 Gallon Capacity Means in Practice
Eight gallons is the standard entry point for contractor portables. It gives you enough buffer for intermittent tool use — framing nailers, finish nailers, brad guns, blow guns — without the compressor running continuously. For high-demand tools like impact wrenches or die grinders that pull sustained CFM, an 8-gallon tank will cycle the compressor frequently. That is the nature of the size class, not a defect.
If your application demands more air storage, Cast Air also offers a 20-gallon portable tank (available as the complete kit 20P150C). For most finish and framing work, the 8-gallon is the right balance of portability and capacity.
Build Options: Tank-Only vs. Complete Kit
The 8P150D is the tank-only option. If you need a complete portable unit with wheels, axle, handle, and vibration pads already included, Cast Air offers the 8P150DC complete kit. The kit approach saves approximately 15% versus sourcing those components separately, and everything is matched to fit.
Order the 8P150D (tank only) if:
- You already have wheels, axle hardware, and a handle from a previous build
- You are replacing just the tank on an existing compressor
- You have a custom mounting or cart arrangement in mind
Order the 8P150DC (complete kit with casters) if:
- You are building a new portable compressor unit from scratch
- You want one part number that covers the full portable assembly
- You want the 15% kit savings on the wheels, axle, and handle
Non-Code Rating Explained
The 8P150D is rated non-code. For portable compressor tanks at this pressure (150 PSI) and volume (8 gallons), ASME code certification is not required by most regulatory frameworks. These are the same tanks used in standard contractor and light shop compressors. Cast Air manufactures them to quality standards appropriate for their rated service pressure — the non-code designation reflects the regulatory classification, not a shortcut in materials or construction.
If your application requires ASME-coded tanks — for instance, a permanent shop installation in a jurisdiction that mandates it — Cast Air makes coded tanks in larger sizes. For portable compressor use, the 8P150D is the correct choice.
Tank Accessories Available Separately
If you need wheels, axle hardware, or a handle to complete your build, Cast Air offers these individually:
- W7.5x1.5x.5: 7.5" x 1.5" x 1/2" bore wheel
- W10x1.5x.5: 10" x 1.5" x 1/2" bore wheel
- W10x3x.75: 10" x 3" x 3/4" bore wheel
- AB12: Axle bolt 1/2" for 8-gallon portable
Or skip the individual parts and order the 8P150DC complete kit.
Why Buy From Air Compressor Factory Direct?
- Specialist supplier: We stock Cast Air OEM tanks and parts direct from the Minnesota manufacturer. What you see is what ships — not a generic substitute.
- Free shipping on qualifying orders
- Free technical support: Call 866-217-0063. If you are unsure whether the 8P150D or 8P150DC fits your build, we can walk through it with you before you order.
- Full manufacturer warranty on all Cast Air tanks
- Honest upgrade guidance: If the 8-gallon is too small for what you are running, we will tell you and show you the options. We would rather you buy the right tank once.
Call 866-217-0063 for quick answers and help!
