WELDING AND CUTTING SAFETY PROCEDURE
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.
This procedure shall apply to all employees responsible for planning, supervising, and conducting welding and cutting operations.
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