Air-Pressurized Water Extinguishers
APW stands for "air-pressurized water." APWs are large, silver extinguishers which are filled about two-thirds of the way with ordinary tap water, then pressurized with normal air. In essence, an APW is just a giant squirt gun.
APWs stand about 2 feet tall and weigh approximately 25 pounds when full. They are designed for Class A (wood, paper, cloth) fires only.
POINTS TO REMEMBER ABOUT WATER EXTINGUISHERS