to break off, and the sudden release of gas from a
--Before starting to work, make sure that the
welding machine frame is grounded, that neither
full cylinder may cause it to take off like a rocket.
terminal of the welding generator is bonded to the
frame, and that all electrical connections are
--Always open cylinder valves slowly. (Do not
securely made. The ground connection must be
open the acetylene cylinder valve more than 1 1/2
attached firmly to the work, not merely laid loosely
--Close cylinder valves before moving cylinders.
--When using portable machines, take care to
see that the primary supply cable is laid separately
--Never attempt to force unmatching or crossed
so that it does not become entangled with the
threads on valve outlets, hose couplings, or torch
welding supply cable.
valve inlets. The threads on oxygen regulator
outlets, hose couplings, and torch valve inlets are
--When stopping work for any appreciable
right-handed; for acetylene, these threads are
length of time, be SURE to de-energize the
left-handed. The threads on acetylene cylinder
equipment. When not in use, the equipment should
valve outlets are right-handed, but have a pitch that
be completely disconnected from the source of
is different from the pitch of the threads on the
oxygen cylinder valve outlets. If the threads do not
match, the connections are mixed.
--Keep welding cables dry and free of oil or
grease. Keep the cables in good condition, and at
--Always use the correct tip or nozzle and the
all times take appropriate steps to protect them
correct pressure for the particular work involved.
from damage. If it is necessary to carry cables some
This information should be taken from tables or
distance from the machines, run the cables
worksheets supplied with the equipment.
overhead, if possible, using adequate supporting
--Do not allow acetylene or acetylene and
oxygen to accumulate in confined spaces. Such
SAFETY OF PERSONNEL
mixtures are highly explosive.
If it is necessary for a welding operator to work
--Keep a clear space between the cylinders and
on platforms, scaffolds, or runways at an elevation
the work so that the cylinder valves may be reached
of more than 5 feet, provisions should be made to
quickly and easily if necessary.
prevent falling. This can be accomplished by the
use of a railing or some other equally effective
--When lighting the torch, open the acetylene
valve first and ignite the gas while the oxygen valve
is still closed. Do not allow unburned acetylene to
Helmets or hand shields should be used during
e s c a p e and accumulate in small or closed
all arc welding or arc cutting operations. Goggles
should also be worn by personnel in the vicinity of
arc welding or cutting operations to protect eyes
--When extinguishing the torch, close the
from injurious rays from adjacent work and from
acetylene valve first and then close the oxygen valve.
flying objects. The goggles may have either clear
glass or colored glass, depending on the amount of
--When welding or cutting is stopped for a
exposure to adjacent welding operations. Helpers
period of 15 minutes or more, or when the operator
or attendants should be provided with proper eye
leaves the area, the equipment must be secured.
Precautions for the operation of metal-arc
Goggles or other suitable protection should be
welding equipment include the following:
used during all gas welding or oxygen cutting
--Use only approved welding equipment, and be
sure that it is in good condition.