T.O. 1-1A-9
2-209. To provide proper eye shielding, goggles, helments and shields will be carefully selected and will have the proper
shade lens as follows:
a.
For electric and inert gas metal arc weldings, clear and filter lenses up to and including shade No. 2 will be used
for resistance welding. These lens will also be used to protect eyes from stray light and from other nearby welding
operations. For fusion arc welding, filter lens will be shade No. 6 for use up to 30 amperes, shade No. 8 for 30 to 75
amperes, shade No. 10 for 75 to 200 amperes, shade No. 12 for 200 to 400 amperes and shade No.14 for above 400
amperes.
b.
For gas welding/cutting Shade No. 5 filter lens will be used for light cutting and welding, shade No. 6 for
medium work and shade No. 8 for heavy work.
2-210. VENTILATION. Forced ventilation will be used in welding operations when natural ventilation is insufficient and
will not prevent the accumulation of dangerous gases and fumes. In confined spaces, the use of exhaust fans/blowers is
usually effective. When the concentration of hazardous (toxic) fumes cannot be kept within safe limits, all exposed
personnel will wear appropriate breathing devices. Areas subject to accumulation of explosive gases/vapor will be
brought within safe limits before and will be kept within safe limits during complete welding operations. Appropriate gas
detecting devices, explosimeters, etc., will be utilized to determine condition of area atmosphere and that it is within safe
limits.
CAUTION
When in doubt about an operation, the Hygiene Officer or Fire Marshall will be contacted for
directions before proceeding and all applicable data in AFM 127-101 will be reviewed.
2-211. FIRE/EXPLOSION HAZARDS. Welding will not be permitted near flamm2hle or explosive materials until all
necessary safety precautions have been taken. Fire extinguishers with the correct charge for the type of fire that may be
involved (Class A, B, or C), will be provided and readily available during all welding operations. In addition to the above,
the following precautions shall be taken:
a.
Flammable Materials. Before attempting any welding operation, all flammable materials will be removed from
the immediate area. Wooden floors, and other combustible surfaces/materials will be protected against excessive heat.
When it is impractical to remove flammable materials from the area, protect with a suitable fire resistant shield, i.e.,
asbestos blankets, metal shields, etc. Inspect area at regular intervals during and after completion of the welding
operation to detect possible sources of potential fire.
b.
Explosion Hazards. Welding will be prohibited where flammable gases or liquids may be ignited until the
possibility of explosion or fire has been eliminated. In confined spaces, where ventilation is inadequate, welding itself
may produce flammable and explosive vapors.
c.
Fire Protection. When a fire hazard still exists after precautionary measures have been taken, no welding will be
accomplished, until a decision to weld is made by the Fire Marshal and a fully equipped fire guard is standing by the
welding operations.
2-212. HANDLING AND CARE OF COMPRESSED GASES FOR WELDING. The precautions given below shall be
complied with in the handling of oxygen and other gases used in welding operations:
a.
Gas cylinders sh2ll be stored only in approved, assigned spaces where there is minimum danger of the cylinders
being damaged or knocked over.
b.
Compressed gas cylinders will be kept away from external sources of heat and highly combustible materials.
c.
Oxygen cylinders will not be stored inside, in the same location with cylinders of fuel gases, i.e., propane, butane,
acetylene, etc.), unless they are well separated. A fire -proof partition will be placed between oxygen and compressed
fuel gases when it is necessary that they be stored in the same general location/compartment or room.
d.
Cylinders stored in the open will be protected from ice, sleet, snow and the direct rays of the sun. Cylinders
containing oxygen will be placed as far as possible from containers of combustible gases.
e.
When cylinders are moved by crane or derrick, suitable cradles, boats or platforms will be used. Slings or
electric magnets shall never be used to move cylinders of compressed gases.
f.
Trucks and dollies suitably designed for such purposes will be used to transport and move compressed gas
containers.
g.
Oxygen cylinders and fittings will be kept free of oil and grease. Although oxygen will not burn, it will support
combustion, causing oil and grease to burn with greater intensity. Oxygen under pressure can produce sufficient heat
when released in the presence of oil or grease to cause explosion/fire.
2-112
