On each of our engines, One 2.5 gallon water can mixed to 10% Cold Fire (9 quarts water/1 quart Cold Fire) & a 20 lb. ABC dry chem. This gives us a coverage from Class A to some Class D fires. The water can at that mixture will put out a small aluminum, titanium, or magnesium fire (like you would find in vehicle fires) along with kicking butt on a Class A fire.
Yes, we do have a built in air hose connection on each of our engines and we carry the air hose/chuck and the supplies to refill our cans on the scene.
I never thought on this. I always kept considering the uses not such things.
foam fire extinguisher