WELDING AND CUTTING SAFETY PROCEDURE
PURPOSE
This Procedure provides safety and
health instructions regarding gas and electric welding, cutting, brazing, or
similar flame or spark-producing operations to protect personnel and property
against heat, evolved gases and fumes, electrical shock, and radiation.
SCOPE
This procedure shall apply to all employees responsible
for planning, supervising, and conducting welding and cutting operations.
GENERAL
INFORMATION
A. Supervisors
and workers performing welding, cutting, and/or brazing operations shall be
trained in hazard recognition, evaluation, and control; fire protection; and
safe work practices; and shall adhere to requirements in this procedure.
B. Welding/Cutting Areas: Whenever
possible, welding and/or cutting operations should be performed in areas that
are isolated and designated for such uses.
Welding or cutting must not be performed in the following areas:
1. In the
presence of explosive atmospheres;
2. In areas near the
storage of quantities of exposed, ignitable materials;
3. In
sprinklered buildings while such protection is impaired; or,
4. In areas
not authorized by management or by a hot work permit.
C. Whenever
welding operations are interrupted for a substantial period of time (e.g.,
lunch or overnight) or completed, "hot" metal areas must be
identified, and the equipment must be shut off with any valves closed.
D. Equipment: Personnel are required to use approved
welding, cutting, and grinding equipment and follow the manufacturer’s
instructions. Such equipment shall be
maintained in safe working order at all times.
Personnel shall report any equipment defect or safety hazard to a
supervisor, and the use of such equipment must be discontinued until it is
repaired by qualified personnel.
E. Site Preparation: Prior to beginning welding or cutting
operations, workers must:
1. Check the work area (35' radius) to
ensure that no fire hazards including oily or greasy materials are present;
2. Remove
all combustible materials within 35’ not necessary for the operation. Any combustible material that cannot be
removed, such as wood platforms, should be covered with a flame-resistant
material;
3. Check
that all equipment is in good working condition;
4. Inform
workers in the immediate area and display warning signs at the worksite to
alert others of the potential hazards;
5. Install
welding shields/curtains to protect other workers from the sparks and intense
light associated with welding/cutting operations; and
6. When performing welding, cutting,
and/or brazing operations in areas on or around Acutely Hazardous Materials
which are included in a Process Safety Management (PSM) Program, a hot work
permit is required.
F. Ventilation: Cutting or welding
operations must be performed in areas with adequate ventilation to keep fumes
and gases within safe limits.
1. Local exhaust ventilation must be used
when potentially hazardous materials are being worked on. (Examples of potentially hazardous materials
include, but are not limited to, chromium, fluorides, zinc, beryllium, cadmium,
lead, and mercury).
2. Adequate
exhaust ventilation must be used when using inert-gas welding, plasma-arc
cutting or carbon-arc cutting.
3. The
metal surface shall be free of all chlorinated solvents during any welding or
cutting operations.
G. Personal Protective Equipment: Approved
personal protective equipment (PPE) shall be worn by all employees performing
or assisting in welding and/or cutting operations.
1. Examples
of PPE include eye protection, helmets and hand shields, flame resistant
gloves, limb/body protection, and respiratory protection.
2. While
performing overhead or vertical welding, personnel must wear leather personal
protective equipment (shoulder, head, and ear covers).
3. All
welders should wear flame-resistant aprons, coveralls, gauntlet gloves and
shirts with sleeves of sufficient length and construction to protect the arms
from heat, UV radiation, and sparks.
4. Wool
and leather clothing are preferred because they are more resistant to
deterioration and flame than cotton or synthetics. Synthetic fiber clothing should not be worn
unless it is specifically manufactured to be fire retardant.
5. Clothing
should be kept reasonably free of oil or grease.
6. Front
pockets and upturned sleeves or cuffs should be prohibited. Sleeves and collars should be kept buttoned
and high boots should be worn under pant legs (or leggings worn) to prevent hot
metal slag or sparks from contacting the shin.
7. Personnel
must wear respiratory protection when ventilation is not sufficient to prevent
exposure above permissible limits. (When
performing cutting or welding operations involving coatings which generate
toxic substances upon heating, or working with materials that contain
beryllium, cadmium, lead, or mercury, personnel must wear supplied-air
respirators).
8. Workers
welding on metal alloys should wear work uniforms, coveralls, or similar
full-body coverings that are laundered each day. Lockers or other closed areas should be
provided to store work and street clothing separately.
9. Other
personnel in welding/cutting areas not protected by noncombustible or
flameproof screens or shields must wear appropriate goggles.
H. Confined Space Operations: Proper
precautions must be taken by personnel who are required to perform welding or
cutting operations in a confined space area.
Refer to the Confined Space Pre-Entry Procedure, and contact the Entry
Supervisor prior to performing welding or cutting operations in a confined
space.
I. Prior
to welding tanks, cylinders, or other containers, supervisory personnel must
complete a hot work permit and shall verify that such containers do not
contain, or have not contained, any flammable, toxic, or explosive materials. If containers have contained flammable,
toxic, or explosive materials, they must be emptied, flushed, or otherwise
purged and sampled prior to welding.
J. Fire Protection: Fire protection
equipment must be maintained ready for use at all times that welding or cutting
operations are being performed.
1. Utility
trucks supporting welding/cutting operations must be equipped with fire
fighting and fire protection equipment, including a fire extinguisher of at
least 10 A:B:C rating.
2. If welding
is to be performed in areas where a fire hazard may exist, fire watch practices
must be established and implemented.
(See Appendix A Hot Work Permit.)
3. When
performing welding or cutting operations on coated surfaces that are highly
flammable (determined by a flammability test), the coating must be stripped
from the area to prevent ignition.
K. All
surfaces covered with toxic preservatives, including coatings which generate
toxic substances upon heating, must be stripped for a distance of at least 4
inches from the area of heat application.
L. Contractors
performing welding and cutting operations must be made aware of the risks
involved in the operations, and shall obtain approval from District prior to
performing such operations.
FIRE SUPPRESSION
& PROTECTION
A. Suitable
fire protection equipment must be maintained ready for use at all times that
welding or cutting operations are being performed. If welding is to be performed in non-approved
areas, supervisory personnel must complete a hot work permit.
B. A
Fire watch and a hot work permit are required when welding or cutting is
performed where:
1. Combustibles
are closer than 35' to the point of operation, or where there are appreciable
combustibles easily ignited by sparks;
2. Wall,
floor, or other openings within 35' radius that expose combustible materials;
or
3. Combustible
materials are adjacent to the opposite side of metal walls, partitions,
ceilings, or roofs and are likely to be ignited by conduction or radiation.
C. If
required, duties of the Fire Watch include:
1. Using
fire extinguishing equipment to extinguish fires
within the capacity of equipment available;
2. Sounding
an alarm in the event of a fire;
3. Watching for
fires in all exposed areas;
4. Maintaining
a fire watch for at least 1/2 hour (30 minutes) after completion of welding or
cutting operations; and
5. Reporting
any injury, including suspected flash burns, to their supervisor.
HOT
WORK PERMIT
Prior to
performing welding/cutting operations in the following circumstances, a hot
work permit must be completed and approved by the appropriate supervisor.
A. In
locations that have not been designated as welding locations.
B. In
confined spaces.
C. Welding or
cutting tanks, cylinders, or other containers.
D. In
areas where a fire hazard may exist (example: weeds, wood products, fabrics,
etc).
E. In
areas included in the Process Safety Management Program (if applicable).
F. In
areas where combustibles are closer than 35' to the point of operation.
G. In
areas where combustible materials are adjacent to the opposite side of metal
walls, partitions, ceilings, or roofs and areas likely to be ignited by
conduction or radiation.
Copies of open permits must be maintained at the job
site and in the supervisor’s office. Upon job completion, closed permits should
be maintained for three (3) years.
OXY-FUEL WELDING & CUTTING
A. Prior
to beginning welding or cutting operations, workers must check that the
cylinders, regulators, backflow prevention device, flame arrestors, hoses,
clamps, and torches are in good working condition.
B. Oil
or grease must not come into contact with oxygen cylinders, valves, regulators
or other fittings. Do not handle oxygen
cylinders or apparatus with oily hands or gloves, or greasy materials. Do not let oxygen contact oily or greasy
surfaces or clothes, or enter a fuel oil or other storage tank.
C. Fuel
gas and oxidizers must pass through a pressure-reducing regulator prior to
being used. Pressure reducing regulators
must only be used at or below the rated pressures and must be specific to the
type of gas being used. Prior to
connecting a pressure regulator, cylinder valves should be "cracked"
to clear the dust or dirt that might otherwise enter the regulator. This procedure shall be performed away from
other welding work or sparks.
D. Prior
to removing a regulator from a cylinder, personnel must close all cylinder
valves, and release the gas from the regulator.
E. Personnel
must follow the manufacturer's operating procedures for lighting the torch. Generally accepted practices for startup and
shut down follow:
1. Start Up
(a) Open the oxygen valve on
the torch handle and adjust the oxygen regulator to the desired delivery range.
(b) Close the torch handle
oxygen valve.
(c) Open the fuel valve on
the torch handle and adjust the fuel regulator to the required delivery range.
(d) Close the torch fuel
control valve.
(e) Hold the torch in one
hand and the spark lighter in the other.
Open the torch fuel valve approximately one-half turn and ignite the
gas.
(f) Point the torch away
from people and combustible materials.
(g) Keep opening the fuel
valve until the flame stops smoking and bring the flame back to the tip.
(h) Open the torch oxygen
valve until a bright neutral flame is reached.
2. Shut Down
When shutting down the system, first shut off the oxygen,
then the fuel gas. Drain the gas
pressures from the system.
F. Cylinders
must be kept far enough away from the actual welding or cutting operation so
that sparks, hot slag, or flame will not reach them, or fire-resistant shields
must be provided.
CARE
OF COMPRESSED GAS CYLINDERS
A. Compressed
gas cylinders shall be legibly marked identifying the contents.
B. Compressed
gas cylinders shall be stored and transported in the following manner:
1. Valve
end must be up.
2. Outside storage areas must be protected
from direct sunlight, external heat sources, electric arcs, or high
temperatures.
3. Inside storage areas must be
well-protected, well-ventilated, and in a dry location at least 20 feet from
highly combustible materials.
4. Cylinders containing flammable gases
will be stored at least 20 feet from oxygen cylinders.
5. Cylinders shall not be kept in
unventilated enclosures such as lockers and cupboards, or inside the cabs or
passenger areas of vehicles.
6. Valve protection devices must be in
place when cylinders are not in use, and during storage and transport. Valve protection devices must not be used for lifting cylinders.
7. Cylinders must be prevented from
tipping, falling, or rolling.
8. All empty cylinders will be handled and
stored as if they were still pressurized.
C. If
cylinders are found to have leaky valves or fittings which cannot be stopped by
closing the valve, the cylinders shall be taken outdoors, away from sources of
ignition, and slowly emptied. Never put
other workers at risk. If the leak is
large, do not attempt to move the cylinder, evacuate all personnel from the
area and notify your supervisor.
D. Pressurized
cylinders must not be taken into confined spaces.
Post by Indian Safety Association
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