Step 7: Fasten and adjust the lower waist strap which will conclude harness adjustment to secure the equipment to the body.

Step 8: Donning the facepiece is the same as has been previously described.

Step 9: The breathing tube can be connected to the demand regulator any time the wearer desires.

Daily Inspections

Self-contained, demand-type breathing apparatus must be kept perfect to protect it as designed.

The first step to ensure that breathing apparatus is safe for immediate use is daily inspection. The breathing apparatus must be inspected daily by the fire fighter who will be using the equipment. Items that must be daily are as follows:

1. Cylinder air pressure should be no less than 1,850 psi or normal pressure recommended by the manufacturer.

2. The regulator and low-air alarm bell must be tested by opening the tank valve to charge the high-pressure lines and regulator; then, close the tank valve and breathe pressure off the regulator to assure proper operation of "main line valve" and "low-air alarm bell."

3. Check all body harness straps. The harness should be tangle-free and all straps extended to their limit.

4. The facepiece should be checked for cracks, tears, and broken head straps. All head straps should be extended to their limit.

The next two steps, to ensure proper operation of breathing apparatus, are performed immediately after the apparatus has been used. These steps are cleaning and sanitizing and recharging air cylinders.

A poorly maintained breathing apparatus is not only unsafe to use, but in most cases, very unpleasant. Dirty moving parts may not work. A facepiece that has not been cleaned and sanitized is not only unpleasant to wear but can spread cold and influenza germs throughout a departmen t. An air cylinder with less air than prescribed by the manufacturer renders the apparatus inefficient or useless.

The facepiece should be thoroughly washed with warm water, any mild commercial disinfectant, and then rinsed with clear, warm water. Special care should be given to the exhalation valve to ensure proper operation. The air hose should be inspected for cracks or tears. Then the facepiece should be dried with a lint- free cloth. The entire apparatus, including the storage box, should then be wiped down with a sponge, using the same disinfectant solution.

Periodic Inspection and Care

After each 3-month period, remove the equipment from service and check valves, pressure regulators, gauges, harness, and facepiece. The following functional test and inspection should then be made: check the facepiece, hose, and exhalation valve by inhaling slowly with the thumb over the end of the hose connection. Make the hose connection and check the performance of the regulator. Inhale deeply and quickly. The regulator should supply a full flow to give the user all the oxygen demanded. If, on slow inhalation, a "honking" sound is heard in the regulator, it can usually be stopped by inhaling faster. The sound is caused by the bellows vibrating and in no way affects the performance or safety of the regulator. If the bellows vibrate continuously or excessively, competent technicians recommended by the manufacturer should overhaul the regulator. If the demand valve sticks open slightly (this may be caused by a cold diaphragm), the breathing gas will continue to flow when the wearer is not inhaling. This condition can usually be corrected by "blowing back" on the regulator. Operate the regulator several minutes to exercise the diaphragm and valves before condemning the regulator. With the hose out of the connection, close off the cylinder valve. With 1,980 pi indicated on the regulator gauge, the regulator and the regulator hose assembly should hold the trapped-in pressure.

After 2 1/2 years, the regulator and regulator hose should be returned to the factory or to its representative for test and/or repair. After each 5-year period, these cylinders should be hydrostatically tested. Each cylinder is stamped with the month and the year of manufacture and the date of the last test to meet requirements of the United States Department of Transportation (formerly Interstate Commerce Commission). Always empty cylinders before returning them for service and test.

Testing Cylinder Valve for Leaks

Use a soap solution to inspect the place where the cylinder pressure gauge connects to the valve body and the safety plugs. With the regulator hose and regulator attached to the cylinder valve, open the cylinder valve.