Figure 5 Suitcases
1.3 Structure of the Product
The Self-Contained Breathing Apparatus is a light weight (71327 Model has a weight of 15kg & 71328 has a weight of 12kg) and highly comfortable apparatus that can provide respiratory
protection to the wearer for approximately (71327 Model: 45min & 71328 Model: 60min) in a hazardous environment. The given duration has been estimated based on an average
consumption of 40L/min and fully charged cylinder (Refer to Para. 1.4 Apparatus Duration).
The Self-Contained Breathing Apparatus (71327 & 71328) is composed of an anatomic back frame with harness for perfect and easy donning. Both back frame and harness are flame
retardant, waterproof and antistatic.
In both cases, the cylinder is connected to the back frame with a cylinder valve, designed according to EN 144-1 and a working pressure of 300bar. The cylinder valve is equipped with a
relief valve. It is connected to a first stage regulator which will decrease the high pressure of 300bar to a constant Pressure of
≈
7bar and a flow of >350L/min. The first stage regulator is
also equipped with a relief valve that will open when the air pressure becomes greater than 11bar. From the first stage regulator the air is diverted into two tubes one of high pressure (WP
300Bar) and one of medium pressure (WP 20Bar). The high pressure tube – which is mounted within a tube of medium pressure for protection reasons – is attached to a warning whistle
and a pressure gauge. This tube is under the exact pressure of the cylinder when the cylinder's valve is open. The warning whistle is so designed that when pressure reduces below 50-
60bar, it operates providing a continuous sound of sound pressure level of >90dB (A), warning the user that the air is dropping down. The medium pressure tube is under pressure of 7bar
and is connected via a fast joint to the second stage regulator (“on demand'' valve) and the full face mask. The joint of the second stage regulator to the face mask provides a capability of
rotation by 360º for easier connection and more comfortable fitting. A plug-in interface is used to connect the “on demand” valve to the face mask.
1.4 Apparatus Duration
The working duration of 45min and 60min of the Self-Contained Apparatus 71327 and 71328 respectively was estimated for an average breathing air consumption of 40L/min in ambient
temperature and fully charged cylinders. However, the actual consumption might vary due to the following affecting factors:
a)
Workload: Adverse work conditions can cause increase of breathing rate and as a result increase of consumption.
b)
Physical fitness of the wearer: A bad physical fitness of the wearer can affect/ increase the air consumption.
c)
Inconvenience in movement: Heavy and restrictive clothing demand bigger effort in movement and this would lead to increased air consumption.
d)
Emotional stress and fatigue can also affect the duration of the devices.
1.5 Air quality of the equipment
The quality of breathing air used for filling the Self-Contained Breathing Apparatus conforms to EN 12021- “Respiratory protective devices - Compressed Air for breathing apparatus”. The
concentration limits of the breathing air components are described in the table below:
Table. 1 Concentration Limits of Breathing Air Components
Element
Oxygen
Lubricants
Odoure & Taste
Carbon dioxide
Carbon monoxide
Water
Content
21±1%
3
Droplets or mist
≤
0,5ml/m
Without
3
≤
500ml/m
3
≤
15ml/m
No free liquid water
Maximum water content of air at atmospheric pressure
Nominal
Pressure
Bar
Maximum water content
of air at atmospheric
3
pressure mg/m
40 to 200
>200
50
35
Figure 4
Face piece
Visor
Lock button
Plug in
interface
Exhalation
valve
Head net
Rubber straps
Facial seal
Each SCBA shall be used together with an approved lifeline as part of the fire-fighters outfit according to FSS Code Ch.3.2.1.3. This lifeline to be capable of being attached by means of a
snap-hook to the harness of the apparatus or to a separate belt in order to prevent the breathing apparatus becoming detached when the lifeline is operated.
LALIZAS
