Self Contain Breathing Apparatus (SCBA SET)

Self Contain Breathing Apparatus (SCBA SET) 

The SCBA Apparatus

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.