Unimag Uni-flame Instruction Manual

GAS WELDING / FLAME CUTTING

AND GOUGING KIT

Instruction manual

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INSTRUCTION MANUAL FOR UNI-FLAME

GAS WELDING, FLAME CUTTING AND GOUGING KIT

UNI-FLAME GAS WELDING EQUIPMENT

Dear customer,

Congratulations on your excellent choice of oxy/acetylene welding and cutting equipment.
The UNI-FLAME range of gas welding and cutting equipment has been rigorously tested by independent laboratories and con­form to the following AUSTRALIAN STANDARDS for gas welding and cutting processes:

Regulators AS4267 including the PROMOTED IGNITION TEST
Gas hose AS1335
Flash arrestors AS4603

This manual refers to safety measures that must be adhered to for safe operation of your Uni-Flame gas cutting and welding
equipment. Please read and understand these warnings and instructions before use. Failure to do so could result in serious
injury or death. Uni-Flame gas cutting and welding equipment should only be used by operators who are properly trained and
qualified in the safe use of this type of equipment.

Technical information in this Instruction Manual is based upon information available in two Expert Technology Tools published
by the Welding Technology Institute of Australia (WTIA):
WTIA Technical Note 5 Flame cutting of steels (1996)
WTIA Technical Note 7 Health and safety in welding (2004)

Further information and copies of these publications, and technical support in welding and related activities, are available from
WTIA Tel: [phone] Fax; [phone] or email [e-mail]. For information about other publications
and the activities of the WTIA and WGA visit www.wtia.com.au. or www.unimig.com.au

General Safety Information

Safety consideration for both the operator and his surroundings must be given to the heat source produced by mixing
compressed oxygen with a fuel gas and igniting the resulting mixture.
When using any of these processes, particular safety considerations apply in respect of:

a) Burns from flames, hot objects, malfunctioning hand-held equipment, molten particles etc.
b) Explosion from mixed gas concentrations created by fuel gas leakage from cylinders, bulk supplies, hoses, welding

equipment breakable connections, etc.
c) Fire caused by ignition of flammable materials, leakage of fuel gases, contact with hot slag, welding equipment in
poor condition etc. Plant, buildings, ship and bush fires have occurred.

d) Ignition of materials not normally considered flammable due to oxygen enrichment
e) Violent rupture or explosion of components due to being pressurised beyond their design pressures.
f) Asphyxiation due to displacement of atmospheric, breathable air by inert or toxic gases, e.g. leakages in confined

spaces or lack of oxygen resulting from excessive rusting in confined spaces

g) Radiation damage (to eyes principally and other exposed surfaces).
h) Fumes originating from the particular materials being welded, heated or cut.
i) Electric shock which could result when gas welding or cutting on cables or other conductors at high voltage.
j) Influence on the workplace from the above hazards (containers, vessels, heights, etc).

Gas Properties and Particular Hazards

Gases Used

The flames used in gas welding, cutting and allied processes are obtained by the ignition of mixtures of oxygen and
appropriate fuel gases, the most common being acetylene and LPG.
All of these fuel gases, especially when mixed with compressed oxygen, are capable of releasing very large amounts of energy
in the form of heat or explosion, requiring minimum energy to start the reaction.
Consequently, they should be treated with great care and in accordance with well defined safety procedures.
Some industrial gases may be flammable, oxidising, toxic or corrosive, and users need to take special precautions in handling
them. Users should always have on hand Material Safety Data Sheets, normally available from Gas Suppliers, for each of the
gases stored and used at any location.

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The properties of these and other commonly used gases are listed in the table below.

This table summarises the properties, characteristics and hazards of the more common gases used in gas welding, cutting and
allied processes.

PHYSICAL AND SAFETY PROPERTIES OF GASES

Notes
1 LP Gas consists primarily of Propane (C3H8) - other constituents include artificial odourisers for safety
2 Approximate calculated values only - there is some scatter in the literature.
3 N/S = Not specified in this Standard

Oxygen

Cylinder colour is black. Oxygen has no smell, and is generally considered non-toxic at atmospheric pressure.
Oxygen normally constitutes 21% of air and when the concentration of oxygen exceeds 21%, flammable materials become
increasingly easier to ignite and burn more rapidly and with a higher flame temperature. Oxygen itself does not burn, but
supports and accelerates combustion in other substances including those not normally considered combustible and which
may be readily ignited by sparks. Metals may also burn. Hence, great caution must be exercised in preventing oxygen
enrichment of the atmosphere, particularly in confined space situations. Oxygen should never be called "air".
Oxygen in contact with oil, grease, other hydrocarbons or oil based substances can cause spontaneous ignition and
consequential fire or explosion. Hence all oxygen systems (e.g. cylinders, pipework, regulators, blowpipes) must be kept
completely free of oil or grease.
Proper advice should be sought, e.g. from Gas Suppliers and Equipment manufacturers, before using any materials for oxygen
service, especially lubricants, seals and thread sealants, including PTFE tape, which have not been supplied for use with
oxygen and marked accordingly.
When the oxygen concentration in the atmosphere is less than 21%, gradual and sometimes undetectable changes occur in
operator's alertness and efficiency.
Each year many accidents ranging from minor to fatal types occur through either misuse of oxygen or failure to understand its
properties and their significance.
Some lessons which have been learnt through misuse or unsafe use of oxygen are:
a) DO NOT use oxygen to refresh air: There is often a temptation to use oxygen to 'sweeten' air when welding or cutting
operations have been carried out in confined spaces. Large amounts of oxygen can be released locally in a short time
from gas cylinders under pressure. In one situation where this was done, hot work in the form of flame cutting was

INSTRUCTION MANUAL FOR UNI-FLAME

GAS WELDING, FLAME CUTTING AND GOUGING KIT

CHART 1

Property Oxygen Acetylene LP Gas
(O2) (C2H2) (C3H8)
Note 1

Density relative to air 1.103 0.901 1.52 to 2

Ignition limits V% - in air - 2.5 to 80 2.2 to 9.5

Ignition limits V% - in oxygen - 2.5 to 80 2 to 57

Ignition temp ∞C - in air - 423 554

Ignition temp ∞C - in oxygen - 428 530

Flame temp in air (Note 4) - 2325 1925

Flame temp in oxygen (Note 4) - 3100 2800

Smell Odourless Pungent (Sweet) Pungent

Colour Colourless Colourless Colourless

Gas cylinder colour (AS 4484) Black Maroon Silver/Grey

Regulator colour (AS 4267, AS 4480) Black Red Orange

Welding Hose colour (AS 1335) Blue Red Orange

Safety device colour (AS 4603) Blue Red Red

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carried out with a subsequent ignition of worker's clothes and fatal burns.
b) TAKE CARE in confined spaces: Do not leave blowpipes or hoses connected to the supply gases within confined
spaces during work breaks or overnight. Even slow leaks can result in very hazardous situations, with possible fire and
explosion on re-ignition of the blowpipe.
c) VENTILATE confined spaces: In flame cutting not all of the oxygen released from the cutting nozzle is necessarily used
in cutting. In confined spaces this may result in a dangerous increase in oxygen content in the air, pointing to the need
for adequate ventilation in such situations.
d) DO NOT use oxygen as a substitute for compressed air: There are many examples of this situation where oxygen has
been used, such as in cleaning, resulting in serious and fatal accidents due to fire or explosion from spontaneous
ignition. NEVER use oxygen to start engines, drive air tools etc.
e) DO NOT use oxygen or compressed air to dust off clothes. Clothes can become readily flammable and even
self-igniting through oxygen enrichment.
f) DO NOT KINK pressure hosing: Kinking or nipping hose to interrupt gas flows or whilst changing torches is a very
dangerous practice. Gas can still bleed through the system, or more seriously, escape rapidly should the operator lose
his grip or the hose rupture.

Fuel Gases

Each of the fuel gas-oxygen combinations warrants care in use, from handling of the gas supplies through to the point of
intended ignition. There are greatly increased risks of fire and explosion in the case of leaks. Asphyxiation is also possible due
to exclusion of air in leakage situations.
All fuel gases have special properties, which warrant additional precautions:
a) Acetylene:
Cylinder colour is Claret / Maroon. Acetylene has a distinctive garlic smell. It is non-toxic, but asphyxiation is possible
through depletion of oxygen. Acetylene is lighter than air and not likely to collect in ducts and drains, but could collect in roof
spaces. It requires minimum energy to ignite in air or oxygen. A concentration of as little as 2.5% in the air can burn. Acetylene
is a potential fire and explosion hazard. Adequate ventilation and leak free systems are required. Hot metallic particles or hot
slag can cause ignition of leaks remote from the area where welding or cutting is taking place.
This gas, in its free state under pressure, may decompose with explosive violence. For this reason it is supplied in special
cylinders . Explosions can occur in pure acetylene subjected to excessive temperature or pressure. Mechanical shock to the
cylinder due to mishandling, or overheating when under high pressure, may also cause decomposition, giving rise to high
temperatures and possible detonation even in the absence of oxygen. Another possible cause of detonation is flashback in
welding, heating or cutting blowpipes, and safety devices are recommended in blowpipe gas supply.
Under certain conditions, acetylene can react with metals such as copper and silver to produce explosive acetylides. This
places a restriction on materials which can be used for the construction of pressure regulators, other equipment and piping.
Copper alloys containing more than 70% copper or 43% silver should never be used with acetylene.
Free acetylene must never be used outside the cylinder at pressure exceeding 150 kPa gauge.
The properties of acetylene are taken into account in systems developed for its storage and supply, and with adherence to safe
procedures, dangerous situations will not arise.

b) Liquefied Petroleum Gas (LPG):

Cylinder colour is aluminium. LPG is usually supplied as a mixture of gases with propane as the main constituent.
Standard LPG has been odourised and has a fish-like smell. It is non-poisonous, but may cause asphyxiation through depletion
of oxygen.
It is denser (heavier) than air and will collect in low or confined spaces, e.g. ducts, drains, basements, boats, ships and closed
tanks. A concentration of as little as 2.2% in the air can burn. It is a fire and explosion hazard, and requires minimum energy to
ignite when mixed with air or pure oxygen. LPG will ignite and burn instantly from a spark or piece of hot metal.

Gas Supply

General

Your Uni-Flame gas welding and cutting equipment is designed to be used by gases delivered to the point of use from porta­ble compressed gas cylinders. In all cases, gas supplies may be subject to statutory or regulatory provisions. Many Australian
Standards cover the subject. The location, separation, allowed quantities and signage of gas storage should be in accordance
with the relevant statutory requirements and manufacturer's provisions.

INSTRUCTION MANUAL FOR UNI-FLAME

GAS WELDING, FLAME CUTTING AND GOUGING KIT

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Cylinder Types and General Care

Cylinders used for oxygen, acetylene, LPG, are in effect thin walled highly pressurised vessels. Due to the presence of gases
under pressure, full or partially filled cylinders can cause serious injury or damage should they rupture.
Also, slow leakage of gas may result in a high risk of fire or explosion or the possibility of asphyxiation. Oxygen, hydrogen,
carbon dioxide and inert gas cylinders, are fitted with a bursting disc safety device. LPG cylinders have a spring-loaded
pressure relief valve.
Acetylene cylinders differ from those used for other gases in that they are filled with a porous substance saturated with
acetone in which the acetylene is dissolved under pressure. Acetylene is unstable and highly reactive at high pressure. The
porous substance or filler is therefore intended to quench heat of spontaneous decomposition and reduce the risk of
explosion. Fusible safety plugs are fitted in the shoulder of the cylinder to permit the gas to escape rather than the cylinder
explode in the event of overheating.
Because of these factors and the particular properties of the stored gases , particular care is always required in the handling
and usage of cylinders as follows:
a) Cylinders are generally obtained on loan or hire from gas suppliers. This allows the periodical testing specified in
Australian Standards and statutory regulations to be carried out by the owner.
b) Do not tamper with the markings or colour codings of cylinders. Do not use cylinders without labels/colour code.
Do not guess contents - return cylinder to supplier.
c) Refilling of cylinders must be carried out only by competent organisations with the correct gas and with the owner's
approval. Refilling with any other gas is not permitted.
d) Gas should only be used for the particular intended purpose, e.g. never use oxygen for cleaning (dusting), or to
provide ventilation or to support breathing.

e) Gases should only be identified by their correct name so as to avoid dangerous mix-ups.
f) Never attempt to disguise or repair damage to a cylinder such as denting. Such cylinders must not be used until

advice is obtained from the gas supply company.
g) Valve seats and outlets should be protected by keeping all kinds of dirt and contamination away from cylinders,
especially during connection and disconnection. Grit, loose fibres and other dirt may lodge in connectors and on
valve seats causing leaks or are picked up by high velocity gas streams, causing hot spots in regulators potentially
resulting in ignition . Organic matter such as oil, grease and hydrocarbon liquids which may ignite spontaneously in
high pressure oxygen is another hazard to regulators and other downstream equipment. Any damage to valves or
outlets should be reported.
h) Avoid flame impingement from the welding or cutting blowpipe. Keep cylinders away from all sources of artificial
heat (furnaces, boilers, radiators, flames). The fusible plugs at the top of an acetylene cylinder are particularly sensitive
to heat and operation can lead to an extensive acetylene flame vertically from the top of the cylinder.

i) Do not tamper with safety devices.
j) Return cylinders with the valve closed.

Cylinder Storage, Transport, Handling and Use

Storage

All storage areas must comply with statutory requirements. Australian Standard AS 4332:1995. Dangerous Goods Regulations
give complete requirements.
Cylinder storage areas should be well ventilated and away from sources of heat. External storage is preferred. Protection from
weather is desirable but not at the expense of ventilation. Other products should not be stored with cylinders, especially oil,
paints or corrosive liquids. Oxygen cylinders must be separated from fuel gas cylinders by a distance greater than 3 meters.
LPG cylinders in excess of 50 kg total capacity should not be stored within 3 meters of any other cylinders, including acetylene.
Cylinders should always be stored upright and restrained to prevent falling. Full cylinders should be segregated from empty
ones and fuel gases from oxygen. "NO SMOKING OR NAKED LIGHTS" signs should be displayed where fuel gases are
stored.

Transport

Take sensible precautions and ensure ADG Code and other regulatory requirements are met.
Use open vehicles wherever possible. If closed vans or cars have to be used make sure they are properly ventilated at all times.

INSTRUCTION MANUAL FOR UNI-FLAME

GAS WELDING, FLAME CUTTING AND GOUGING KIT

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Ensure all valves are fully closed and that there are no leaks. Secure cylinders against movement within the vehicle. Do not
allow any part of the cylinder to protrude from vehicle (this prohibits cylinders being carried horizontally across forklift tines).
Disconnect all equipment (e.g. pressure regulators) from cylinders. Do not use cylinders in a closed vehicle.
Acetylene and LPG cylinders must be transported upright even when empty (this ensures that the safety device is in contact
with vapour and not liquid).

Handling

Do not move cylinders with the cylinder valves open.
Never lift a cylinder with magnets, chains or a sling. Use a cradle when lifting cylinders by crane. Never roll a cylinder along the
ground. This damages the identification labels, and may cause the valve to open. Use a trolley for manual handling. The trolley
should incorporate a heat shield because of the proximity of the fuel gas to the oxygen cylinder .

Cylinder Use

The manufacturer's instructions and recommendations should always be followed.

a) Never "crack" a fuel gas cylinder valve when adjacent to any ignition source.
b) Damaged valves or regulators or those suspected to be damaged should not be used until checked by a qualified

service agent/organisation or person.

c) Cylinders must never be used as rollers to assist moving other objects.
d) Acetylene and LPG cylinders must always be in the vertical or near vertical position when in use and when empty
e) Acetylene can only be used to a maximum pressure of 150 kPa (gauge). With increasing pressure explosion may occur

due to instability of this gas.
f) Opening of cylinder valves should only be carried out with approved keys or hand wheels. Do not use excessive
force or extension key to open or close cylinder valves.
g) Acetylene valves should not be opened more than about one and a half turns, one turn is preferable to allow for
quick closing in an emergency.

h) Empty cylinders should have the valves closed, any protective caps fitted and be suitably identified, eg "MT" in chalk.

Connection to regulators and hoses

Keep the cylinder valve clean, especially its outlet connection. No grit, dirt, oil or dirty water should be present. Particles of dirt
and residual moisture may be removed by "cracking" open the valve momentarily and then closing it. Note: great care must be
taken when "cracking" as serious injuries can occur.
Make sure the Uni-Flame pressure regulator is suitable for the gas and pressure in the cylinder and that its inlet connection is the
same thread as that in the cylinder valve. Fuel gas connections have left handed threads. Never force any connection that does
not fit.
Open the cylinder valve slowly using its hand wheel or a suitable key for key-operated cylinder valves. Do not over tighten
the spindle when shutting off the valve as this will destroy the soft seating material in the valve. If the valve spindle is too
stiff to turn with the hand wheel or the correct key, do not increase the leverage on the spindle and return the cylinder to the
gas supplier.

Equipment Specifications and Assembly

General

Uni-Flame gas cutting and welding equipment has been properly designed, manufactured and tested independently to meet
Australian standards. It must be maintained and used with full consideration of the hazards inherent to the use of oxy-fuel gas
mixtures detailed previously.

Pressure Regulators and Gauges

Gas cutting and welding applications should never be supplied directly from compressed gas cylinders. A Uni-Flame pressure
regulator must be connected to the gas cylinder to control the pressure of the gas at the welding or cutting blowpipe.
Uni-Flame regulators are fitted with two pressure gauges to allow monitoring of the cylinder contents and the delivery pressure
to the end application.
Although accidents rarely occur as a direct result of regulator failure, care must be continuously exercised because the
potential hazards are severe. This is particularly true of oxygen regulators where ignition and explosion is possible under
adverse conditions.
The following recommendations should be observed in order to ensure continued safe operations:
a) Uni-Flame Regulators should be used only with the gas and maximum cylinder pressure for which they are designed
and labelled (see AS 4267).

b) Never test a regulator for gas leaks with a naked flame.

INSTRUCTION MANUAL FOR UNI-FLAME

GAS WELDING, FLAME CUTTING AND GOUGING KIT

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c) Acetylene and LPG regulators should only be used with the gas for which they are designed. Use of an LPG regulator
on acetylene cylinders could result in exceeding the maximum safe use pressure of acetylene.
d) Regulators having damaged pressure gauges or inlet and outlet connections etc should never be used. Inlet and outlet
connections should never be changed from the original manufacturing specification.
e) Do not use oil or grease on any regulator. Do not handle a regulator with a rag, hands or gloves contaminated with oil
or grease.
f) Keep your regulators clean. When not in use the dust covers supplied to protect the inlet and outlet connections
should be fitted.
g) Never use a regulator that is leaking gas or exhibiting signs of excessive creep (build up of gas pressure when
blowpipe valves are closed). Pressure build up beyond 35kpa is excessive and regulator should be removed from use
and be either replaced or repaired.
h) To avoid damage to regulator, operator must always fully release regulator adjusting knob by turning it in an
anticlockwise direction before opening gas cylinder valve and subjecting regulator to high pressure. Note: never
release the regulator adjusting knob whilst there is pressure in the gas hoses.
i) Ensure regulator is securely attached to gas cylinder before opening cylinder valve and subjecting regulator to high
pressure.

j) Do not stand in front of regulator when opening cylinder valve, always stand to one side.

Hoses and fittings

Requirements

Uni-Flame Hose and fittings for use in gas welding, cutting and allied processes meet the requirements, including colour
coding, specified in AS 1335 and AS 4267.

Colour coding

Use blue hose only for oxygen
It should be noted that AS 1335 specifies different test methods and cover colours for acetylene hose (red) and LPG hose
(orange) . These hoses should never be interchanged.

Location

Hoses should be located and protected from heat, mechanical damage, traffic, sparks, slag, grease and oil so that accidental
damage such as piercing or burning cannot occur. Location of hoses over sharp edges or manifolds or under sparks or hot slag
from welding or cutting should be avoided.

Fittings

These must be as specified in AS 1335, of an appropriate type, securely made and leak tight. Wire should never be used to
fasten hose to fittings. Oxygen fittings have right hand threaded nuts, fuel gases left hand thread nuts. Use only Uni-Flame gas
hoses and connectors when replacement is required.

Length and diameter

It is recommended that the maximum hose length should not exceed fifteen (15) metres for each gas, or such distance which
will allow the operator of hand-held equipment to be in sight of all the supply gas cylinders, whichever is the smaller.

General maintenance of gas hoses

Never use insulation tape to affix hose connections or to attempt repair or lengthening of gas hoses. Do not crimp or kink gas
hoses to temporarily stop gas flow .Gas hoses must be replaced immediately if they show signs of leaking or damage from
flashback burning, physical damage or weakness due to ageing. Examine all hoses regularly for leaks, wear and loose
connections. Gas hoses can be tested for leaks by immersion in water at normal operating gas pressures.

Blowpipes, cutting attachment and mixers

Blowpipes perform the gas control and mixing function with the aid of a gas mixer therefore blowpipe and mixer must
perform the mixing of oxygen and fuel gas with due consideration to potential back-flow of gases and flashback. The following
points must be considered before use
a) The inlet connections are suitable for the welding hose fittings supplied. Never attempt to connect hoses with fittings
that are not compatible. Ensure that all connections are tight and not leaking. Never force a connection.
b) The control valves are clearly marked ‘oxygen’ and ‘fuel’ (by the abbreviations ‘O’ and ‘F’), and colour coded blue for
oxygen and red for fuel same as the welding hose.

c) Only suitable mixers and other attachments should be fitted to a blowpipe.
d) Keep all equipment clean. Do not use oil or grease on any blowpipe, cutting attachment, mixer or accessory to suit.

Do not handle any of these items with a rag, hands or gloves contaminated with oil or grease.

INSTRUCTION MANUAL FOR UNI-FLAME

GAS WELDING, FLAME CUTTING AND GOUGING KIT

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e) Particular attention should be paid to the recommended maximum and minimum operating pressures and flows for
the blowpipe-mixer tip or nozzle combination. These should always be respected.

f) Never hang a blowpipe or gas hose on a regulator or cylinder valve.
g) Never test for leaks with a flame.

Tips, nozzles and their attachment fittings

i) Uni-Flame Tips and nozzles are well identified and carry information relating to their use such as size, recommended

gas pressures and plate thickness to be cut.
ii) Uni-Flame Tips and cutting nozzles appropriate to the particular fuel gas should be used.
See Cutting guide chart 2.1 & 2.2 below for appropriate nozzle recommendation.

iii) It should be noted that tips and nozzles operate safely and efficiently over a limited range of flows. Below a minimum

INSTRUCTION MANUAL FOR UNI-FLAME

GAS WELDING, FLAME CUTTING AND GOUGING KIT

1. CUTTING GUIDE FOR TYPE 41 ACETYLENE NOZZLES

Plate Nozzle Pressure Pressure Cutting Typical
Thickness Size Oxygen Acetylene Speed Consumption
mm kPa kPa mm/min L/min
Oxy Acet

6 8 200 100 450 19 3
12 12 200 100 380 38 4
20 12 250 100 360 45 5
25 15 220 100 320 56 6
40 15 350 100 270 75 7
50 15 400 100 240 84 7
75 15 450 100 180 95 8
*100 20 400 100 150 134 9
125 20 450 100 150 155 10
150 24 450 100 130 211 11
200 24 500 100 100 234 14
250 32 600 100 90 420 20
300 32 600 100 90 420 20

* Maximum thickness recommended for cutting attachments.

2. CUTTING GUIDE FOR TYPE 44 LPG NOZZLES

Plate Nozzle Pressure Pressure Cutting Typical
Thickness Size Oxygen LPG Speed Consumption
mm kPa kPa mm/min L/min
Oxy LPG

6 8 200 100 450 30 3.5
12 12 200 100 380 50 4
20 12 250 100 360 68 4.5
25 15 220 100 320 72 5.5
40 15 350 100 270 90 5.5
50 15 400 100 240 99 5.5
75 15 450 100 180 111 6
*100 20 400 100 150 149 6
125 20 450 100 150 171 6.5
150 24 450 100 130 228 7
200 24 500 100 100 256 9
250 32 600 100 90 456 14
300 32 600 100 90 456 14

* Maximum thickness recommended for cutting attachments.

CHART 2.1

CHART 2.2