How to Properly Use the SCBA Cascade System

SCBAs allow firefighters to breathe in smoke-filled buildings.

Firefighters' self-contained breathing apparatus (SCBA) is probably their most vital piece of equipment to effectively and safely fight a fire inside a structure. The amount of air in the cylinder of the SCBA is directly related to the amount of time a firefighter can survive in a hostile environment of smoke, deadly gas or a low oxygen atmosphere. These bottles must always be filled to maximum capacity to allow the firefighter the maximum amount of time to work. Having full SCBA cylinders can also save the firefighters' lives if the become trapped or incapacitated. These cylinders are filled using a cascade filling station.

Things You'll Need

• SCBA fill station
• Gloves
• Protective eyewear
• Ear protection
• Logbook

Instructions

1. Inspect the SCBA cylinder to be filled for any obvious damage, such as gouges in the outer surface, damaged threads at the hose connection, a damaged operating valve handle or severe scorching from heat. Check the hydrostatic test date of the cylinder to be filled. Aluminum and steel cylinders must be hydrostatic tested every five years and have an unlimited life span as long as they pass testing. Fiber-wrap-composite cylinders must be tested every three years and have a maximum life span of 15 years. Composite-carbon-fiber-wrapped cylinders must be tested every five years and have a 15 year maximum life span.

2. Check the cylinder pressures on the large bottles of the SCBA fill system to be used. The cascade system is usually made up of two to five large cylinders filled with compressed air.

3. Put on the gloves, protective eyewear and ear protection and release a short burst of air from both the cascade system and the cylinder to be filled to check for obstructions.

4. Connect the SCBA cylinder to the fill hose of the cascade system and hand-tighten the connection. The cylinder may be placed in a drum of water to keep it cool from the heat being generated by the pressurized air filling it or it may be "hot filled."

5. Open the large cylinder of the cascade system, then open the valve of the SCBA cylinder. The SCBA cylinder will fill only until the pressure of the two cylinders equalizes. If the pressures equalize and the SCBA cylinder isn't full, close the valve on the cascade cylinder and slowly open the next cylinder of the cascade system. Repeat the process of closing and opening the cascade cylinders until the SCBA cylinder reaches the proper pressure, as specified on the cylinder by the manufacturer.

6. Close the valves of both cylinders after the SCBA cylinder is full. Relieve the pressure in the fill line with the pressure relief valve and disconnect the SCBA cylinder. Log the SCBA cylinder's serial number, date filled and final pressure into the cascade system logbook.

Tips & Warnings

• Always wear gloves, protective eyewear and ear protection when working with high-pressure air cylinders.

• High-pressure cylinders may be dangerous when handled or filled improperly. Always follow the manufacturer's specifications. Don't look at the valves when releasing air or point the valve toward someone, since any loose material in the valve would come out at a high rate of speed and could cause an injury.

References

• Hoyt Breathing Air Products: Hydrostatic Testing Help
• Breathing Air Systems: Number of Small Cylinders That Can Be Filled From Your Storage System