Section 2 − Introduction; Section 3 − Hazardous Events; Section 4 − Hazards Of Recompressing Pure Oxygen - Smith Little Torch Owner's Manual

Inspect all equipment before use. Do not use damaged, defect-
ive, or improperly adjusted welding and cutting equipment.
Make sure levers and valves work properly, threads on equip-
ment are clean (no grease or oil) and not deformed, gauges are
intact and easy to read, regulator is clean and free of oil or dirt,
and fittings are properly sized for the cylinder. Make sure
hoses are clean (no grease or oil) and ferrules are properly in-
stalled so the fitting does not slip inside the hose. Be sure all
connections are tight and there are no leaks in the system.
This booklet offers basic information regarding the Little Torch. Given
reasonable care, the torch will provide trouble-free use for many years.
SECTION 3 − HAZARDOUS EVENTS
The following events are very hazardous and can occur in any oxy-fuel
system. It is important to understand these hazards and know how to
prevent them.
Backfire: The return of the flame into the torch, usually accompanied by
a popping sound. The flame may be extinguished or it may re-appear at
the tip end.
Sustained Backfire: The return of the flame into the torch that contin-
ues to burn inside the torch with a hissing or squealing sound.
Flashback: The return of a flame into and through the torch or into the
hose. In some instances it can reach the regulator and even enter the cylin-
der. This is generally caused by the mixing of the oxygen and fuel gas in the
system. This is a very dangerous situation that can cause an explosion any-
where in the system. This is why purging is so important (Section 7-5 or 8-5).
SECTION 4 − ASSOCIATED HAZARDS OF
RECOMPRESSING PURE OXYGEN
Open oxygen cylinder valves slowly. Opening an oxygen cylin-
der valve quickly can cause a fire or explosion. Be sure regula-
tor adjusting handle is in the full out (off) position before open-
ing an oxygen cylinder valve.
Recompressing high pressure oxygen in a low pressure cavity may cre-
ate heat, resulting in combustion. For combustion to occur, oxygen, fuel,
and kindling temperatures must be present. All of these components
may be present when oxygen is recompressed by opening the tank valve
too quickly.
Oxygen: High purity oxygen accelerates the rate of combustion, in-
creases heat output, and lowers the combustible point at which various
materials will burn.
SECTION 2 − INTRODUCTION
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