Sabre Vision 3 User Instructions - Vision 3
VISION 3
1
1. INTRODUCTION
1.1 BREATHABLE AIR
Air used to supply or charge breathing air
may be natural or synthetic. The
composition of breathable air is given in
Table 1.
Component
Mass %
(Dry Air)
Volume %
(Dry Air)
Oxygen
23.14
20.948
Nitrogen
75.52
78.08
Argon
1.29
0.93
Carbon Dioxide
0.05
0.031 4
Hydrogen
0.000 003
0.000 05
Neon
0.001 270
0.001 818
Helium
0.000 037
0.000 524
Krypton
0.000 330
0.000 114
Xenon
0.000 039
0.000 009
Table 1: Breathable Air
There is an increased fire risk when the
oxygen content is above the value shown
above.
The purity/quality of air used to supply
and charge breathing apparatus should
be tested periodically in accordance with
national regulations.
If
not
specified
otherwise,
the
contaminants shall not exceed the
permissible exposure level.
National regulations must be observed.
The mineral oil content shall be such that
the air is without the odour of oil. The
odour threshold is in the region of 0.3
mg/m
3
.
The water content shall not exceed 50
mg/m
3
for 200 bar apparatus and 30
mg/m
3
for 300 bar apparatus.
For airline apparatus, air must be used
with a dew-point sufficiently low to
prevent internal freezing.
1.2 COMPRESSED AIR
AIRLINE SUPPLIES
Air for use with compressed air airlines
must conform to EN 12021 : 1999 and
must have a dew point sufficiently low to
prevent internal freezing when apparatus
is used in temperatures below 4
°C.
No. of Wearers
Airflow (L/min.)
1
2
3
4
300
450
750
900
Table 2
Airline pressure must be between 5.0 and
9.0 bar (70 and 130psi). Airflow supply
capacity for a single airline is given in
Table 2.
Generally; One wearer requires 300
L/min. Each additional wearer requires
150 L/min, each additional pair of
wearers requires 450 L/min. All
measurements must be taken at the
wearer end of the airline.
Example: for 8 users (4 pairs) the
recommended flow is 4 x (300 + 150) =
1800 litres/minute.
A Sabre airline flow tester is available
from Scott Health and Safety Limited
under Article Number 1035978.
Compressed air airlines must be Sabre
products, approved to EN 139.
Ensure that hoses used in an explosive
or inflammable atmosphere are marked:
ANTI-STATIC – EN 139.
Cost effective PVC hoses may be used in
other atmospheres.
Scott Health and Safety Limited
manufacture a range of anti-static and
PVC hoses, in lengths ranging from 15
metres to 60 metres. Our Customer
Services Department will be pleased to
offer advice on price and delivery.
1.3 APPARATUS DURATION
All durations quoted are nominal, based
on an average wearer consumption rate
of 40 litres per minute and FULLY
CHARGED cylinders. Actual wearer
consumption rates vary due to many
factors, such as:
•
Workload: high work rates increase
consumption rates.