The Cast Air BGAC1x2M Belt Guard Aftercooler Duplex Mounted is a two-unit aftercooler assembly configured for duplex compressor setups — twin-compressor base frames where two reciprocating piston compressor cylinders or two compressor units run from a shared belt guard. If you are running a duplex compressor and dealing with moisture problems in your lines, failing tools, or water in your distribution system, the BGAC1x2M is the purpose-built solution for that specific configuration. It handles the combined discharge from both sides of a duplex compressor in a single mounted unit, using the existing flywheel fan airflow for cooling — the same principle as the single-unit BGAC1M, applied to a dual-compressor setup.
A single BGAC1 or BGAC1M handles one compressor side at 35 CFM. A duplex compressor running two cylinders produces roughly double that output. The BGAC1x2M is engineered for that combined flow — it is not two BGAC1 units plumbed together as an afterthought, it is a purpose-configured assembly designed to mount cleanly on a duplex belt guard and treat the combined discharge from both sides before it enters the receiver tank.
Why Duplex Compressors Need a Purpose-Configured Aftercooler
- Higher Combined CFM Output: A duplex compressor running two cylinders produces approximately double the CFM of a single-cylinder unit at the same HP rating — a single BGAC1 would be undersized for the combined flow from both cylinders
- Combined Discharge Heat: Two pump heads running simultaneously generate more heat in the discharge line than a single-head unit — the aftercooler needs to handle the combined thermal load, not just one side
- Clean Belt Guard Integration: The x2M mounting configuration is designed to fit the duplex belt guard assembly cleanly — no improvised brackets, no mismatched single-unit hardware stacked together
- Single Point Treatment: Treating the combined discharge at one aftercooler is more effective than trying to split the flow to two separate units downstream
Aftercooler Performance and Operation
- Belt Guard Mounted Design: Mounts to the duplex compressor belt guard assembly and uses the flywheel fan airflow for cooling — no separate fan motor or electrical connection required
- Air-to-Air Cooling: Ambient air moves across the finned heat exchanger core, dropping the temperature of compressed air passing through the tubes
- Pre-Tank Cooling: Discharge air is cooled before it enters the receiver tank — moisture drops out at the aftercooler rather than condensing inside the tank and traveling downstream
- Moisture Reduction: Cooling compressed air causes water vapor to condense — less water reaches your filters, regulators, lines, and tools
- Passive Operation: Once installed, the BGAC1x2M operates automatically whenever the compressor runs — there is nothing to switch, adjust, or maintain beyond periodic inspection of the core and drain
Technical Specifications
- SKU: BGAC1x2M
- Type: Belt guard aftercooler, duplex mounted (two-unit configuration)
- Base Unit: BGAC1 (two units in duplex configuration)
- Mounting: Duplex compressor belt guard frame
- Cooling Method: Air-cooled via compressor flywheel fan
- Manufacturer: Cast Air
- Note: Exact combined CFM rating and dimensional specifications for the BGAC1x2M assembly are not published in the standard Cast Air specifications. Call 866-217-0063 with your duplex compressor model number to confirm fitment and combined flow capacity before ordering.
Available Configurations — BGAC Aftercooler Lineup
Cast Air builds belt guard aftercoolers in four single-unit ratings plus duplex configurations. For duplex compressors, the x2M designation indicates a dual-unit assembly configured for duplex mounting:
- BGAC1 / BGAC1M / BGAC1x2M — 35 CFM (single) / duplex: 18" L x 10-1/2" W per core, 3/4" NPT connections, 8 lbs per core — BGAC1 for single compressors (5-10 HP), BGAC1x2M for duplex configurations in that HP range. BGAC1K adds the installation kit hardware for new single-unit installs.
- BGAC2 / BGAC2M — 50 CFM: 18" L x 14-1/2" W, 1" NPT connections, 12 lbs — for single 15 HP compressors.
- BGAC3 / BGAC3M — 75 CFM: 24" L x 20-1/2" W, 1" NPT connections, 20 lbs — for single 20+ HP compressors.
- BGAC4 / BGAC4M — 100 CFM: 23" L x 26-1/2" W, 1" NPT connections, 25 lbs — for larger industrial systems.
If you are running a duplex 15 HP or larger compressor, call us — the correct duplex configuration steps up in size accordingly.
When Does a Shop Need the BGAC1x2M vs. Other Configurations
- BGAC1x2M is correct when: You have a duplex reciprocating compressor — two cylinders or two pump heads running from a shared base frame and belt guard — in the 5-10 HP per side range. The combined output needs a duplex aftercooler assembly, not a single-unit BGAC1.
- Use a single BGAC1M when: You have a single-cylinder compressor in the 5-10 HP range. Running a single BGAC1M handles the full output of one compressor side without needing the duplex configuration.
- The BGAC1K is better for new single-unit installs: If you are adding an aftercooler to a single compressor for the first time and need mounting hardware included, the BGAC1K complete kit handles that without the complexity of the duplex assembly.
- Step up to BGAC2x2M or larger for higher HP duplex setups: If your duplex compressor is 15 HP or above per side, the BGAC1-class unit will be undersized for the combined output. Call us to confirm the correct duplex configuration for your machine.
Typical Applications
- Auto repair and body shops running duplex two-stage piston compressors for high air demand
- Fleet maintenance facilities where a duplex compressor runs multiple air tools simultaneously
- Production and fabrication shops with continuous air demand from plasma cutting, grinding, or pneumatic tools
- Any facility where a duplex compressor is showing moisture problems — water at the drains, corrosion in fittings, air tool failures, or filter service intervals shorter than expected
Why Buy From Air Compressor Factory Direct?
Air Compressor Factory Direct has supplied compressor components and accessories to shops and industrial buyers since 2016. We stock Cast Air aftercooler configurations including the BGAC1x2M for duplex setups and the single-unit BGAC1, BGAC1M, and BGAC1K for standard installations. Free shipping on qualifying orders. Because the BGAC1x2M is a configuration-specific part, we recommend calling before ordering to confirm compatibility with your duplex compressor model — give us the compressor model number and we will verify the fitment. Full Cast Air manufacturer warranty. Our technical team is at 866-217-0063 for direct answers.
Call 866-217-0063 for quick answers and help!
