Foam proportioning and generating devices are essential for accurately mixing and distributing foam concentrate with water (and air) to produce effective fire suppression foam. Each type of device serves specific needs depending on the application, hazard type, and environmental conditions.
Arranged from most common to least, here are the main categories and their typical uses:
Balanced Pressure Proportioners
The most widely used in fixed foam systems, such as those protecting fuel storage tanks, marine terminals, aircraft hangars, and refineries. These devices maintain a steady foam-to-water ratio by equalizing pressures between foam concentrate and water supplies—ensuring consistent performance even during pressure fluctuations.
In-Line Eductors (Venturi Inductors)
Frequently used in portable firefighting setups or manual hose line operations. These compact devices rely on the Venturi effect to draw foam concentrate into the water stream and are ideal for emergency response, maintenance areas, or fuel transfer zones.
Variable Flow Proportioners
Found in complex or large-scale systems like airport hangars, chemical plants, and logistics warehouses, where discharge flow can vary significantly. These proportioners automatically adjust foam injection rates to maintain correct concentration regardless of flow fluctuations.
High Expansion Foam Generators
Designed to produce large volumes of foam with minimal water usage, high expansion foam generators are used in confined or large enclosed spaces such as aircraft hangars, tunnels, LNG facilities, warehouses, and basements. With expansion ratios exceeding 200:1, they displace oxygen and suppress fire by filling the protected volume, making them ideal for total flooding applications.
Other Proportioning Methods
Around-the-Pump Proportioners: Commonly used in mobile fire apparatus (fire trucks and trailers), they divert a portion of the water from the pump outlet to create suction for foam concentrate. These systems are economical and widely used in municipal and industrial firefighting.
Turbine or Water Motor Driven Inductors: Applied in deluge and fixed piping systems, especially where electrical power is limited or unreliable. These devices use the energy from flowing water to drive a proportioning mechanism, offering reliable mechanical operation in industrial or remote setups.
Built with durable, corrosion-resistant materials, all of these systems play a vital role in generating and delivering consistent, high-quality foam to suppress Class B (flammable liquid) and challenging Class A fires. Whether used in manual hose lines, automated suppression systems, or large-area flood protection, foam proportioners and generators are key components in protecting assets across industrial, aviation, marine, and special hazard facilities.