An alternative to compressed-air foam systems for the delivery of Class A foam is a high-pressure foam system. These systems use a highly atomized water/foam combination to offer faster knockdown capability than traditional high-volume systems, which depend on water volume to suppress the fire. A high-pressure foam system uses up to 80% less water than traditional systems.

The high-pressure technology has been around for decades according to Kevin Quinn, president of E.J. Metals. But to simplify its use, he developed a patented triple-discharge nozzle that changes stream types with a flick of the wrist. Quinn also optimized and tested system components, including a specially configured CAT high-pressure pump. Quinn's system can be driven by a gasoline engine, diesel engine or hydraulic system. It can be integrated within a complete apparatus or deployed as a skid unit that can be retrofitted or mounted on new apparatus, or on rough terrain vehicles.

The U.S. Army in Afghanistan has E.J. Metals' Assault Force 70 Fire Rescue Rough Terrain Vehicles. And the U.S. Air Force is currently retrofitting about 300 ARFFs with high-pressure systems for deployment across the globe.

High-pressure foam systems are less expensive than CAFS, yet offer the same range of wet to dry foam with the nozzle developed by Quinn. "You just let off on the trigger and decide whether on a wet foam or if you need a longer reach."

Quinn's local 25-member fire department has five trained CAFS operators and 20 other firefighters. With the high-pressure system, first responders don't have to wait for a CAFS operator. "The system was developed because we tried to make it simple so all the firefighters are as good as each other," said Quinn. "I can change the foam setting at the nozzle and that's it."

Another high-pressure foam delivery system is HMA Fire's Ultra High Pressure (UHP), which offers 1,200 to 1,400 psi and can use most any type of foam, from Class A to AFFF. The system is available in air-droppable, aircraft (C-130) and/or helicopter-deployable configurations.

"With CAFS, you are using compressed air to create the force and the bubbles," said Doug Eno, a sales manager with HMA. "With a UHP foam system, you are using the pressurized water to create the force and this pressurized water combined with the proper nozzle creates smaller water droplets with more surface area that capture more air and thus creates better bubbles."

The air used to create the bubbles is generated from the end of the nozzle to the flame, so users are not introducing new air to the fire. Also, the system has no air compressors or pressurized vessels that require a great deal of maintenance, testing and space, according to HMA's Web site.

• Read the main story, "Steady as She Flows," to learn how to keep your CAF system healthy.