IMPCO MIXER FB225M-2

Core Functionality

The IMPCO Model 225 is a single-diaphragm, air-valve carburetor/mixer designed for LPG (propane vapor) and natural gas applications. It features a down-draft air inlet that allows for either remote air filtration or open-element filters.

The FB designation indicates it is a feedback style mixer, while the “-2” suffix means it comes equipped with a silicone diaphragm for enhanced durability and performance.

Key Features & Specifications

• Fuel Compatibility: Propane vapor (LPG) and natural gas

• Airflow Capacity: Up to 380 CFM (179.3 L/s)

• Power Rating: Approximately 237 hp (177 kW) at 380 CFM with 2.0" in Hg manifold depression

• Operating Temperature: –40 °F to +250 °F (–40 °C to +121 °C)

• Inlet Pressure: –1.5" water column (–0.37 kPa)

• Mounting Orientation: Vertical

• Diaphragm Material: Silicone (offered instead of standard Hydrin for durability)

Additional Functionality

• Feedback Capability: Designed for closed-loop air/fuel control when used with vacuum supplies and sensors.

• Mixture Tuning: Allows fine-tuning of lean air/fuel mixtures using optional shims or ring spacers.

• Flexible Filtration: Accepts both remote filtration and open-element air filter designs.

Summary Table