Scott Sigma 2 User manual

SIGMA 2
Self-contained Breathing Apparatus
User Instructions
Article No. 1035017 Issue G 05. 2010

i
Self-contained Breathing Apparatus
Contents
WARNINGS ...............................................................................................................................................................................ii
1. INTRODUCTION........................................................................................................................................................1
1.1 IMPORTANT ..............................................................................................................................................1
1.2 BREATHABLE AIR ....................................................................................................................................1
1.3 APPARATUS DURATION..........................................................................................................................1
1.4 PERSONNEL TRAINING...........................................................................................................................1
1.5 SERVICING ...............................................................................................................................................2
1.6 SPARE PARTS AND ACCESSORIES.......................................................................................................2
1.7 NOTIFIED BODIES....................................................................................................................................2
2. TECHNICAL DESCRIPTION .....................................................................................................................................2
2.1 GENERAL ..................................................................................................................................................2
2.2 APPARATUS DESCRIPTION ....................................................................................................................2
2.3 PNEUMATIC SYSTEM ..............................................................................................................................4
2.4 REDUCER .................................................................................................................................................4
2.5 DEMAND VALVE .......................................................................................................................................4
2.6 FACEMASKS .............................................................................................................................................5
3. PRE-USE AND MONTHLY CHECKS........................................................................................................................6
3.1 GENERAL ..................................................................................................................................................6
3.2 PNEUMATICS............................................................................................................................................6
3.3 DEMAND VALVE .......................................................................................................................................6
3.4 CHECK FACEMASK..................................................................................................................................6
3.5 POSITIVE PRESSURE, BYPASS AND LEAK TEST.................................................................................7
3.6 WHISTLE TEST.........................................................................................................................................7
3.7 REPLACING CYLINDERS .........................................................................................................................7
3.7.1 Fitting a replacement Cylinder of the same size. .......................................................................8
3.7.2 Fitting a replacement Cylinder of a different size.......................................................................8
4. DONNING PROCEDURE ..........................................................................................................................................8
4.1 HARNESS..................................................................................................................................................8
4.2 DON FACEMASK ......................................................................................................................................8
4.2.1 Head Harness............................................................................................................................8
4.2.2 Head-net ....................................................................................................................................9
4.3 OPEN CYLINDER VALVE .........................................................................................................................9
4.4 FACEMASK SEAL CHECK...................................................................................................................... 10
4.5 BYPASS CHECK ..................................................................................................................................... 10
4.6 LEAK TEST.............................................................................................................................................. 10
4.7 WHISTLE TEST....................................................................................................................................... 10
4.8 CYLINDER PRESSURE .......................................................................................................................... 11
5. DOFFING INSTRUCTIONS ..................................................................................................................................... 11
5.1 REMOVE FACEMASK............................................................................................................................. 11
5.2 TURN OFF CYLINDER ............................................................................................................................ 12
5.3 REMOVE APPARATUS........................................................................................................................... 12
5.4 CLEAN AND CHECK APPARATUS ........................................................................................................ 12
6. AFTER USE............................................................................................................................................................. 12
6.1 CLEAN FACEMASK ................................................................................................................................ 12
6.2 CLEAN APPARATUS .............................................................................................................................. 13
6.3 DEMAND VALVE ..................................................................................................................................... 13
6.4 CHECK APPARATUS.............................................................................................................................. 13
6.5 FIT FULLY CHARGED CYLINDER.......................................................................................................... 13
6.6 LEAK TEST.............................................................................................................................................. 13
6.7 RECORD TEST DETAILS ....................................................................................................................... 14
6.8 STORAGE................................................................................................................................................ 14
7. SCHEDULED MAINTENANCE................................................................................................................................ 14
7.1 MONTHLY................................................................................................................................................ 14
7.2 ANNUALLY .............................................................................................................................................. 14
Registered Office: Scott Health and Safety Limited, Pimbo Road, West Pimbo,
Skelmersdale, Lancashire, WN8 9RA, England.

ii
WARNINGS
Please Read Carefully and Fully Understand
This manual is for use by personnel trained in the use and care of compressed air breathing
apparatus, and MUST NOT be used as a self-teaching guide by untrained users. Failure to
understand or adhere to the SIGMA 2 User Instructions may result in injury or death.
Scott Health and Safety Limited has taken great care to ensure that the information in this
manual is accurate, complete and clear. However, Training and Technical Support
Services will be pleased to clarify any points in the manual and answer questions on
SCOTT breathing apparatus.
The following warnings are in accordance with certifying authority requirements and
apply to the use of breathing apparatus in general:
Breathing apparatus users must be fully trained in the use and care of self-
contained, compressed air breathing apparatus.
Ensure that the selection of the apparatus type is sufficient for the tasks being
undertaken and the hazards likely to be encountered. Please refer to National
Regulations for guidance.
In order to ensure the optimum performance and user safety, the apparatus
must be tested and serviced in accordance with Section 7 and the notes in
Section 1 under Personnel Training and Servicing.
The quality of air used to supply and charge breathing apparatus must meet
the requirements of EN 12021 : 1999. See Section 1 for details.
The wearing of beards, side-burns or spectacles may adversely affect the
sealing of a facemask to the wearer's face.
The apparatus is not designed for use underwater.
The harness must not be used as a vehicle seat restraint.
DISCLAIMER
Failure to follow these instructions or misuse of the apparatus may result in: death,
injury or material damage; and invalidate any warranty or insurance claims.
COPYRIGHT
This manual must not be copied in part or in whole, or used for purposes other than its
intended purpose without the written permission of Scott Health and Safety Limited.

SIGMA 2
1
1. INTRODUCTION
1.1 IMPORTANT
SIGMA 2 must be serviced in accordance
with the Servicing Schedule on at least an
annual basis. Please refer to notes under
Servicing.
These instructions for the use, care and
maintenance of the apparatus must be
followed to ensure the correct and safe
operation of SIGMA 2.
For any enquiries regarding the use of
SCOTT breathing apparatus, please
contact Training and Technical Support
Services at Scott Health and Safety
Limited.
1.2 BREATHABLE AIR
Air used to supply or charge breathing
apparatus 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.
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, 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/m3.
The water content shall not exceed 50
mg/m3for 207 bar apparatus and 30 mg/m3
for 300 bar apparatus.
1.3 APPARATUS DURATION
All durations quoted are nominal, based on
an Average Wearer Consumption Rate of
40 litres/minute and FULLY CHARGED
cylinders. Actual Wearer Consumption rates
vary due to many factors, such as:
1. Workload: high work rates increase
consumption rates.
2. Weight of apparatus and use of
heavy or restrictive clothing.
3. Work environments with extremes of
heat or cold.
4. Physical fitness of the wearer.
5. Other factors include emotional
stress and fatigue.
It is important that all wearers are aware of
these factors and take account of them
when assessing cylinder duration.
1.4 PERSONNEL TRAINING
Personnel who use self-contained,
compressed air breathing apparatus must
be fully trained in accordance with these
instructions and national regulations.
These instructions cannot replace an
accredited training course run by fully
qualified instructors in the proper and safe
use of SCOTT breathing apparatus.
Please contact Training and Technical
Support Services or your distributor for
training course details.
Training and Technical Support
Services:
Scott Health and Safety Limited
Pimbo Road,
West Pimbo,
Skelmersdale,
Lancashire,
WN8 9RA,
England.
Tel: [phone]
Fax: [phone]

SIGMA 2
2
1.5 SERVICING
SIGMA 2 must be serviced at scheduled
intervals by personnel who have completed
a formal training course and hold a current
certificate for servicing and repairing
SCOTT breathing apparatus. Details of the
servicing schedule are contained in the
SCOTT SIGMA 2 Service Manual, copies of
which can only be obtained by registered
holders of a current certificate.
Your distributor or Training and Technical
Support Services can provide training
course details and quotes for service
contracts. Please see above for contact
details.
1.6 SPARE PARTS AND
ACCESSORIES
Our Customer Services Department
provide an efficient, friendly, customer
contact point for ordering new apparatus,
spare parts and accessories. The team can
also provide general information on SCOTT
products.
Customer Services:
Scott Health and Safety Limited
Pimbo Road,
West Pimbo,
Skelmersdale,
Lancashire,
WN8 9RA,
England.
Tel: [phone]
Fax: [phone]
1.7 NOTIFIED BODIES
Inspec International Limited (0194)
56 Leslie Hough Way,
Salford,
Greater Manchester,
M6 6AJ,
England.
BSI Product Services (0086)
Kitemark House,
Maylands Avenue,
Hemel Hempstead,
HP2 4SQ,
England.
2. TECHNICAL
DESCRIPTION
2.1 GENERAL
SIGMA 2 is a self-contained, open circuit,
compressed air, positive pressure,
breathing apparatus, approved to EN 137
(self-contained open circuit breathing
apparatus). It is 'CE' marked in accordance
with Council Directive 89/686/EEC.
SIGMA 2 is approved for use at sea by:
Lloyds Inspectorate, in accordance with
SOLAS regulation 17 and the 1980
Merchant Shipping Act.
Please call Scott Health and Safety
Limited for further apparatus approval
details.
2.2 APPARATUS
DESCRIPTION
SIGMA 2 has a lightweight back-plate and
harness. The two stage pneumatic system
consists of a first stage reducing valve; and
a Demand Valve (DV) that is attached by a
bayonet fitting, to the positive pressure full
facemask.
The back-plate is injection moulded
polyamide/glass/carbon composite, with a
fully adjustable flame retardant polyester
webbing harness. The KevlarTM cylinder
band is fully adjustable and can
accommodate one cylinder from the range
listed in Table 2. A glass-filled polyamide
cam-lock buckle facilitates quick and easy
cylinder replacement. A lumbar pad,
fabricated from flame retardant polyester
and packed with flame retardant closed cell
foam, cushions the weight of the apparatus.
It is attached to the lower back-plate by
means of press-studs. Pneumatic hoses
run in channels moulded into the inner
back-plate. Hose retaining clips are
moulded on the edge of the channels. A
cylinder valve retainer on the lower back-
plate provides a secure mounting for the
cylinder valve.

SIGMA 2
3
Cylinder Types Water
Volume
(litres)
Charging
Pressure
Free Air
Volume
(litres)
Nominal
Duration
(minutes)
Warning
Period
(minutes)
Total
Duration
(minutes)
Cylinder
Charged
Weight
(Kg)
CYL-1200 6.0 207 1200 22 8 30 8.8
CYL-HWG-1200 6.0 207 1200 22 8 30 7.2
CYL-FWC-1300 4.7 300 1300 25 7 32 5.0
CYL-1640 6.0 300 1640 33 8 41 12.5
CYL-HWG-1640 6.0 300 1640 33 8 41 10.0
CYL-FWC-1640 6.0 300 1640 33 8 41 6.3
CYL-1800 9.0 207 1800 33 12 45 13.0
CYL-HWG-1800 9.0 207 1800 33 12 45 11.2
CYL-FWC-1800 9.0 207 1800 33 12 45 6.75
CYL-FWC-1860 6.8 300 1860 37 9 46 6.75
CYL-2240 11.0 207 2240 41 15 56 14.4
CYL-FWC-2460 9.0 300 2460 50 12 62 8.8
Table 2: Cylinders approved for use with SIGMA 2
Cylinder Material is identified by codes within the Cylinder Type. Table 3 identifies the
meaning of the cylinder material code and the specification to which the cylinder is
manufactured:
Code Material Specification
No Code Steel (e.g.: CYL-1200) BS5045 Pt.1
HWG Hoop Wrapped Glass Fibre (e.g.: CYL-HWG-1200) HSE-AL-HW1
FWC Fully Wrapped Carbon (e.g.: CYL-FWC-1300) HSE-AL-FW2
Table 3: Cylinder Codes and Specifications
Durations are nominal and based on an Average Wearer Consumption Rate of 40 L/min and
are for fully charged cylinders.
Total Duration = Cylinder Free Air Capacity
Average Wearer Consumption Rate
Nominal Duration = Total Duration minus the Warning Period.
Warning Period = Cylinder Water Capacity x Whistle Operating Pressure
Average Wearer Consumption Rate

SIGMA 2
4
2.3 PNEUMATIC SYSTEM
The first stage pressure reducer has an
integral cylinder connector hand-wheel.
There is a sintered bronze particle filter in
the reducer inlet.
A high pressure PTCFE lined hose supplies
air to a shoulder mounted pressure gauge
and warning whistle.
The pressure gauge has a stainless steel
case and a polycarbonate, impact resistant,
splinter-proof lens. A blow-out vent prevents
over pressurisation of the case. A rubber
shroud provides mechanical protection.
The warning whistle operates at 55 bar.
Table 2 details the Warning Period for each
apparatus and cylinder combination.
If the hose, whistle or gauge become
damaged, a restrictor in the reducer body
limits air loss to 25 litres/minute.
2.4 REDUCER
The pressure reducer is a simple spring
and piston device that reduces the pressure
of air from the cylinder to a medium
pressure of between 5 and 9 bar. The
operation is automatic and self-regulating
such that the reducer requires no
adjustment.
In the unlikely event of a malfunction in the
reducer, resulting in an uncontrolled rise in
the output pressure, a pressure relief valve
protects the medium pressure system.
A reinforced hose supplies medium
pressure air to the DV.
2.5 DEMAND VALVE
SIGMA 2 is available with two types of
Demand Valve (DV):
•Instant air positive pressure DV (blue)
•First breath-activated DV (black).
Both types of DV have a supplementary
flow bypass and operate in conjunction with
the spring-loaded facemask exhalation
valve to maintain a positive pressure within
the facemask.
The DV senses the changes in facemask
air pressure that occur when the wearer
breathes; and uses this to regulate the
supply of air to the facemask. The DV is
attached to the facemask by a quick-fit
bayonet connection with a spring loaded
locking catch.
Instant Air Demand Valve
The instant air DV supplies air to the
facemask when the cylinder valve is
opened.
First Breath Demand Valve

SIGMA 2
5
The first breath version can be shut by
pressing a reset button on the DV and
opens when the wearer takes the first
breath. This permits the DV to be removed
from the face-piece while the cylinder valve
is open, without loss of cylinder air.
The bypass provides a constant flow of air
in the unlikely event that the regulator
malfunctions in a ‘no flow’ mode.
The bypass is opened by turning the knob
through 90°. As use of the bypass
consumes cylinder air rapidly, it must only
be used to escape from the hazardous
area.
2.6 FACEMASKS
SIGMA 2 is approved for use with: Vision
3, PanaSeal and PanaVisor full
facemasks, all of which conform to EN 136.
All are available with 5-point, fully
adjustable web or net head harnesses and
neck-straps. An inner mask minimises CO2
dead space and visor misting. A speech
diaphragm is fitted.
Vision 3 Facemask with Head-harness
PanaSeal is suitable for medium and
smaller face sizes. PanaVisor is suitable
for medium to larger face sizes. Vision 3 is
available in three sizes: small, medium and
medium/large.
PanaSeal/PanaVisor Facemask with
Head-net
Vision 3 is moulded in grey silicone, while
PanaSeal and PanaVisor are non-
dermatitic black neoprene, or blue silicone.

SIGMA 2
6
3. PRE-USE AND
MONTHLY CHECKS
3.1 GENERAL
1. Check that all parts are clean and
undamaged.
2. Ensure that the shoulder harness is
fully slackened and that a fully charged
cylinder is securely attached to the back-
plate. Replace discharged cylinders.
3. Check that the harness slides freely
through buckles.
4. Check that the facemask visor is
clear and free from marks and damage that
might impair vision. Fully slacken head-
harness straps.
5. Apparatus that fails any of these
checks must be serviced in accordance
with the SIGMA 2 Service Manual.
3.2 PNEUMATICS
1. Check cylinder connector O-ring is
clean and undamaged.
2. Screw hand-wheel connector firmly
into the cylinder valve outlet.
3. Check that pressure gauge, whistle
and hoses are in good condition and are
not kinked or stretched.
3.3 DEMAND VALVE
1. Check that the DV O-ring is clean and
undamaged.
2. Fit the DV to the facemask and check
that the locking catch clicks into place.
Gently twist the DV to ensure that it is
securely fitted.
3. Check that the bypass valve is closed
(flat area on knob is toward the face-piece).
4. On first breath DVs only, press the
black reset button.
3.4 CHECK FACEMASK
1. Don the facemask (see Section 4.2).
2. Open the cylinder valve and check
that the cylinder is full.
3. Check that the facemask pressurises.
If necessary adjust the mask to obtain a
leak tight fit. DO NOT over-tighten the
harness as this distorts the mask.

SIGMA 2
7
3.5 POSITIVE PRESSURE,
BYPASS AND LEAK TEST
1. Insert fingers in the facemask seal
and check there is a steady flow of air out of
the mask.
2. Remove fingers and allow mask to re-
seal.
3. Open the bypass and check there is a
steady flow of air into the facemask.
4. Close the bypass.
5. Close the cylinder valve, hold your
breath, and monitor the pressure gauge for
10 seconds. Check that the reading does
not drop during this period.
3.6 WHISTLE TEST
1. With the cylinder valve still closed,
monitor the pressure gauge and breathe
down air in the system. Check that the
whistle sounds clearly at between 50 and
60 bar.
2. Release head-harness and remove
the facemask.
3. Apparatus that passes all of these
checks is now ready for use.
3.7 REPLACING CYLINDERS
1. Check that the cylinder valve is
closed and slowly undo the cylinder
connector hand-wheel. Remove the reducer
from the cylinder.