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.
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
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
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
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.