Hot Work Training

Training Instructor: George Bunker - george@im-inc.com - 970-632-4917

Course Duration: 00:27:19

Managers and Supervisors

• Establish safe areas for welding and cutting operations.
• Provide training for all employees whose task includes heat, spark, or flameproducing operations such as welding, brazing, or grinding.
• Develop and monitor effective hot work procedures.
• Provide safe equipment for hot work.
• Provide proper and effective PPE for all hot work.
• Monitor all hot work operations.
• Ensure all hot work equipment and PPE are in safe working order.
• Allow only trained and authorized employees to conduct hot work and conduct routine inspections of the hot work area.
• Ensure that the Hot Work Inspection Checklist is used for all hot work outside the authorized safe welding areas.

Employees

• Follow all hot work procedures.
• Properly use appropriate hot work PPE.
• Inspect all hot work equipment on a routine basis.
• Report any equipment problems or unsafe conditions.

General

A Hot Work Inspection Checklist must be completed before performing any hot work operations outside of the Safe Hotwork Area. A Hot Work Inspection Checklist must also be completed on a weekly schedule for all safe hotwork areas. Before cutting or welding is permitted, the area shall be inspected, and a written Hot Work Inspection Checklist shall be used to authorize welding and cutting operations. The Hot Work Inspection Checklist can be found at: www.im-safety.com in the “Permits” tab.

Where practicable all combustibles shall be relocated at least 35 feet from the work site. Where relocation is impractical, combustibles shall be protected with flameproof covers, shielded with metal, guards, curtains, or wet down the material to help prevent ignition of material.

Ducts, conveyor systems, and augers that might carry sparks to distant combustibles shall be protected or shut down.

Where cutting or welding is done near walls, partitions, ceilings, or openings in the floor (grating, manholes, etc.), fire-resistant shields or guards shall be provided to prevent ignition.

If welding is to be done on a metal wall, partition, ceiling, or solid decking/flooring, precautions shall be taken to prevent ignition of combustibles on the other side, due to conduction or radiation of heat.  Where combustibles cannot be relocated on the opposite side of the work, a fire watch person shall be provided on the opposite side of the work.

Welding shall not be attempted on a metal partition, wall, and ceiling or decking/flooring constructed of combustible sandwich panels.

Cutting or welding on pipes or other metal in contact with combustible walls, partitions, floors, ceilings, or roofs shall not be undertaken if the work is close enough to cause ignition by combustion.

Cutting or welding shall not be permitted in the following situations:

• In areas not authorized by management.
• In sprinkled buildings while such protection is impaired.
• In the presence of potentially explosive atmospheres, e.g. flammables.
• In areas near the storage of large quantities of exposed, readily ignitable materials.
• In areas where there is dust accumulation of greater than 1/16 inch within 35 feet of the area where welding/hot work will be conducted.

All dust accumulation shall be cleaned up before welding or hot work is permitted.

Whenever welding or cutting is performed in locations where other than a minor fire might develop or any of the conditions mentioned above cannot be met, a fire watch shall be provided.

• The fire watch shall be provided during and for a minimum of 30 minutes past the completion of the welding.
• The fire watch shall be trained in the use of fire extinguishers and the facility's alarm system.
• During this time the fire watch will have appropriate fire extinguishers readily available.
• Suitable extinguishers shall be provided and maintained ready for instant use.
• A Hot Work Inspection Checklist will be issued on all welding or cutting outside of the designated welding area.
• A Hot Work Inspection Checklist shall be conducted for all authorized safe welding areas on a weekly schedule.

Fire Prevention Measures

A designated welding area shall be established to meet the following requirements:

• Floors swept and cleaned of combustibles within 35 feet of work area.
• Flammable and combustible liquids and material will be kept 35 feet from work area.
• Adequate ventilation providing 20 air changes per hour.
• At least one 10-pound dry chemical fire extinguisher shall be within 35 feet of the work area.
• Protective dividers such as welding curtains or noncombustible walls will be provided to contain sparks, slag, and light to the combustible free area. 

Requirements for welding conducted outside the designated welding area:

• Portable welding curtains or shields must be used to protect other workers from the light generated within the welding area.
• A Hot Work Inspection Checklist must be completed prior to initiating welding operations.
• Respiratory protection is mandatory unless an adequate airflow can be established to pull the fumes away from the workers.
• Plastic materials must be covered with welding tarps during welding procedures.
• Fire Watch must be provided for all hot-work operations outside the authorized safe welding area.
  Fire watch shall remain in the are for 30 minutes after the hot work occurs.

Fumes, Gases and Dust

Fumes produced by some welding processes can be toxic and may require source extraction. An assessment of the work to be performed must be completed before each job is undertaken. Fumes generally contain particles from the material being welded. Welding fumes can have an acute effect on the respiratory system.

Any welding, cutting, or burning of lead base metals, zinc, cadmium, mercury, fluorides, beryllium or exotic metals or paints not listed here that could produce dangerous fumes shall have proper ventilation or respiratory protection.  This includes inert-gas metal-arc welding or oxygen cutting of stainless steel.

Welders and helpers will refer to the Company Respiratory Protection Program to determine the appropriate respiratory protection to be used during welding operations.

All welding and cutting operations shall be adequately ventilated to prevent the accumulation of toxic materials. This applies not only to the welder, but also to helpers and other personnel in the immediate vicinity.

Personal Protection

• Helmets and hand shields shall be made of a material, which is an insulator for heat and electricity. Helmets, shields, and goggles shall not be readily flammable and shall be capable of withstanding sterilization.
• Helmets and hand shields shall be arranged to protect the face, neck, and ears from direct radiant energy from the arc.
• Helmets shall be provided with filter plates and cover plates designed for easy removal.
• All parts shall be constructed of a material, which will not readily corrode or discolor the skin.
• Goggles shall be ventilated to prevent fogging of the lenses as much as practicable.
• All glass for lenses shall be tempered, substantially free from scratches, air bubbles, waves, and other flaws. Except when a lens is ground to provide proper optical vision correction, the front and rear surfaces of lenses and windows shall be smooth and parallel.
• Lenses shall bear some permanent distinctive marking which may readily identify the source and shade.

The following is a guide for the selection of the proper shade numbers.  These recommendations may be varied to suit the individual's needs:

Welding Operation	Shade Number
Shielded metal — arc welding 1/16, 3/32, 1/8-5/32 inch electrodes	10
Gas-shielded arc welding (nonferrous) 1/16, 3/32, 5/32 inch electrodes	11
Gas-shielded arc welding (ferrous) 1/16, 3/32, 1/8, 5/32 electrodes	12
Shielded metal arc welding: 3/16, 7/32, 1/4 inch electrodes	12
Shielded metal arc welding: 3/16, 5/16, 3/8-inch electrodes	14
Atomic hydrogen welding	10-14
Carbon arc welding	14
Soldering	2
Torch brazing	3-4
Light cutting, hp to 1 inch	3-4
Medium cutting, 1 inch to 6 inches	4-5
Healy cutting, 6 inches or over	5-6
Gas welding (light) up to 1/8 inch	4-5
Gas welding (medium) 1/8 - 1/2 inch	5-6
Gas welding (heavy) 1/2 inch or over	6-8

NOTE:

In gas welding or oxygen cutting where the torch produces a high yellow light, it is desirable to use a filter or lens that absorbs the yellow or sodium line in the visible light of the operation. All filter lenses and plates shall meet the test for transmission of radiant energy prescribed in ANSI Z87.1 — 1968 — American National Standard Practice for Occupational and Educational Eye and face Protection. Booths and screens shall permit circulation of air at floor level. Workers or other persons adjacent to the designated welding areas shall be protected from the rays by noncombustible or flameproof screens or shields or shall be required to wear appropriate goggles.

Adequate hand protection and clothing must be used to protect the body from welding hazards.

Cleaning Compounds

In the use of cleaning materials, because of their possible toxicity or flammability, manufacturer instructions shall be followed.

• Degreasing and other cleaning operations involving chlorinated hydrocarbons shall be so located that no vapors from these operations will reach or be drawn into the atmosphere surrounding any welding operation.
• In addition, trichloroethylene and perchloroethylene shall be kept out of atmospheres penetrated by the ultraviolet radiation of gas-shielded welding operations.

Oxygen cutting, using a chemical flux, iron powder, or gas shielded arc cutting for stainless steel shall be performed using mechanical ventilation adequate to remove the fumes generated.

Cylinders

Compressed gas cylinders shall be DOT-approved and legibly marked near the shoulder of the cylinder for the purpose of identifying the gas content with either the chemical or trade name of the gas.

• All compressed gas cylinder connections must comply with ANSI B57. 1-1965 Standards.
• Compressed gas cylinders shall be always secured in an upright position except if necessary for short periods of time while cylinders are actually being hoisted or carried.

All cylinders shall be kept away from sources of heat and from radiators and piping systems that may be used for electrical grounding purposes. Cylinders and cylinder valves including couplings and regulators shall be kept free from oily or greasy substances and must not be handled with gloves or rags in the same condition.

Stored oxygen cylinders shall be kept at least 20 feet from the fuel gas cylinders or combustible materials, especially oil or grease, or separated by a non-combustible barrier at least 5 feet high with a fire rating of at least one-half hour. All empty cylinders shall have closed valves and valve protection caps shall always be in place and hand-tight except when cylinders are in use or connected for use.

Cylinders shall not be kept in unventilated enclosures such as lockers and cupboards.

Fuel gas cylinders stored inside buildings shall be limited to a total capacity of 2000 cubic feet (300 pounds) of liquefied petroleum gas, except for those in actual use or attached ready for use.

All acetylene cylinders shall be stored valve-end up.

Assigned storage spaces shall be located where cylinders cannot be knocked over or damaged by falling objects or subject to tampering by unauthorized persons.

• Back flow protection shall be provided by an approved device that will prevent oxygen from flowing into the fuel-gas system or fuel from flowing into the oxygen system.
• An approved device that will prevent flame from passing into the fuel-gas system shall provide flashback protection.
• An approved pressure-relief device set at the appropriate pressure shall provide backpressure protection.

Special care must be taken when transporting gas cylinders:

• Cylinders must be secured with valve cap installed.
• Cylinders shall not be lifted by the valve protection caps, the regulators must be removed, and cylinders shall not be dropped or permitted to strike each other.
• Removed regulators must be carried in the cab of the vehicle.
• Cylinders shall not be tampered with, nor should any attempt be made to repair them.
• They shall be handled carefully - rough handling, knocks, or falls are liable to damage the cylinder, valve, or safety device and cause leakage.

Safety devices shall not be tampered with.

Arc Welding and Cutting

All personnel operating, installing, and maintaining welding equipment shall be qualified or trained to operate and maintain such equipment.

• All workers assigned to operate or maintain equipment shall be familiar with the respective equipment. Electrical welding equipment shall be chosen for safe operation and comply with applicable Requirements for Electric Arc
• Welding Standards to include: 29 CFR 1910.254, 29 CFR 1910.252 (a)(b) (c) and if gas shielded arc welding is done the worker must be familiar with the
• American Welding Society Standard A6-1-1966.
  
  • Arc welding equipment must be designed to meet respective conditions for which it will operate.
  • It shall be operated at recommended voltage in accordance with the manufacturer recommendations.
  • All leads shall be periodically inspected and replaced if insulation is broken, or splices are unprotected.
  • Leads shall not be repaired with electrical tape.
• All ground connections shall be checked to determine that they are mechanically strong and electrically adequate for the required current.
   

A disconnecting switch or controller shall be provided at or near each welding machine along with over-current protection.

All direct current machines shall be connected with the same polarity and all alternating current machines connected to the same phase of the supply circuit must be connected with the same polarity.

• To prevent electrical contact with personnel, all electrode holders shall be placed where they do not make contact with persons, conducting objects, or the fuel of compressed gas tanks.
• Cables with splices within 10 feet of the holder shall not be used.

If the object to be welded or cut cannot readily be moved, all moveable fire hazards should be removed.

If an object to be welded or cut cannot be moved and if all the fire hazards cannot be removed, then guards shall be used to confine the heat, sparks, and slag and to protect the immovable fire hazards.

Resistance Welding

All personnel operating, installing, and maintaining welding equipment shall be qualified or trained to operate and maintain such equipment.

• Voltage, interlocks, guarding, grounding, and shields shall be in accordance with manufacturer recommendations.
• Precautions such as flash guarding, ventilation, and shields shall be provided to control flashes, toxic elements, and metal fumes.

If the object to be welded or cut cannot readily be moved, all moveable fire hazards should be removed.

Oxygen Fuel Gas Welding and Cutting:

Only approved apparatuses such as torches, regulators, or pressure-reducing valves, setting generators, and manifolds shall be used:

• Mixtures of fuel gases and air or oxygen may be explosive and must be guarded against.
• All hoses and hose connections shall comply with the Compressed Gas
• Association and Rubber Manufacturers' Associations' applicable standards.
• Workers in charge of the oxygen or fuel-gas supply equipment, including generators, shall be instructed and deemed competent by the Company before being left in charge.

If the object to be welded or cut cannot readily be moved, all moveable fire hazards should be removed.

Fire Watch Requirements

A fire watch shall be present when welding, cutting, brazing and/or soldering is performed near combustible materials and/or locations where fire may develop:

• Locations where other than a minor fire might develop.
• Combustible materials are closer than 35 feet to the point of operation.
• Combustibles that are 35 feet or more away but are easily ignited.
  Wall or floor openings within a 35 feet radius of exposed combustible materials.
• Combustible materials are adjacent to the opposite side of metal partitions, ceilings or roofs.

Fire watch personnel shall be maintained at least 30 minutes after welding or cutting operations have been completed.