Self Contain Breathing Apparatus (SCBA SET)
The SCBA Apparatus
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| SCBA SET |
The SCBA worn by
the correctional professional has a positive pressure system; meaning that
there is air always moving to the face piece.
This is different from a demand system that provides air to the wearer
only on demand for example when the wearer takes a breath. The positive pressure system will not allow toxic
gases to enter the wearer’s face piece if there is a bad seal. The air in the face piece will escape through
the bad seal, not allowing the toxic gases to penetrate.
The SCBA Components
There are four
components of a SCBA.
A) Backpack and harness assembly
The
backpack holds the air cylinder. The
harness assembly is made up of adjustable straps that secure the backpack to
the wearer.
B) Air cylinder assembly
Air
cylinders come in a variety of sizes and types depending on manufacturer and
wearer’s needs. Cylinders we use contain
2,216 psi, with an approximate use time of 30 minutes. Composite cylinders weigh approximately 9.5
pounds; steel cylinders weigh approximately 24 pounds. Also included is the high pressure hose.
C) Regulator assembly
Air
from the cylinder goes through the high pressure hose to the regulator
assembly. The regulator reduces the air
pressure from the cylinder to slightly above normal air pressure. The regulator also controls the flow of air
to the wearer. The location of the
regulator varies depending on the manufacturer.
On some regulators there are two knobs. One is the mainline valve; the other is the
emergency bypass valve. The knobs are
different in shape and location. When in normal use, the mainline valve is
always open and emergency bypass valve (which is different in shape and color
from the main line valve) is closed. On
some regulators there is a pressure gauge.
The regulator pressure gauge should read within 100 psi of the cylinder
pressure gauge. Somehow connected to
this system is a low pressure alarm that sounds when cylinder pressure gets in
the 450 psi to 550 psi range depending on manufacturer.
SCBA
Components cont’d:
D) Face piece assembly
The
lens, an exhalation valve, and if the regulator is not attachable, a low
pressure hose. The low pressure hose
brings air from the regulator to the face piece. The face piece is held to the wearer’s head
by adjustable straps.
Donning the SCBA
There are a
variety of ways the SCBA maybe stored – in a wall cabinet, a bag on the wall,
in a box on the floor. No matter the way
the unit is stored, the basic steps of donning the SCBA are the same.
A)
Check air cylinder pressure.
B)
Turn on the air cylinder all the way.
C)
Listen for the low air alarm.
D)
Quickly check the straps to make sure they
are extended.
E)
Check the regulator gauge to make sure
it’s within 100 psi of the air cylinder gauge.
F)
Quickly check your face piece assembly to
make sure the straps are extended and not damaged.
G)
Don the backpack assembly, tighten the
shoulder straps, buckle the waist belt and tighten it.
H)
Don the face piece assembly and tighten
the bottom straps first then the top straps.
Check the face piece for a seal.
I)
Attach the regulator to the face piece
assembly. Depending on the style of
equipment this can be done directly or with the low pressure hose.
J)
Take a breath and exhale checking the
exhalation valve.
Maintenance and Inspection
SCBAs should be
inspected daily using the following steps.
A)
Check the air cylinder pressure. If it is less than 1,500 psi, change the air
cylinder.
B)
Turn on the unit checking the regulator
gauge. Also, listen for the low pressure
alarm. Check the mainline valve and
emergency bypass valve to make sure they are in the proper positions and
operational.
C)
Check the hose connections to make sure
they are tight and there are no leaks.
D)
Check the face piece assemblies to make
sure the straps are extended and the assembly is not damaged in any way.
E)
Check the harness assembly to make sure
the straps are fully extended and not damaged.
F)
If there is anything wrong with the unit
take it out of service immediately and informed the proper personnel at your
facility.
SCBA
Testing
Certain parts of
the SCBA assembly need periodic testing such as the regulator. Field personnel do not do this. Staff should never try to repair the
regulator or open it up. The air
cylinders need periodic testing. This
test is called a hydrostatic test and cannot be done by field personnel.
common sense rules
These are some
more common sense rules for using the SCBA in search and rescue.
A) Know
you and your buddy’s limitations;
B) Know
the limitations of the equipment you are using;
C) Bring a
light;
D) Know an
alternate route out;
E) Use a
radio;
F) Use a
tag line; and
G) Stay
low.
