API RP 54 Section 20 - Hotwork, Welding, and Flame Cutting Operations

20.1 General

    20.1.1 A written safety work permit system covering welding and flame cutting operations shall be observed on all drilling and service rigs.
    20.1.3 Welding and flame cutting operations shall not be permitted close to flammable liquids, accumulations of crude oil, escaping gas, or locations where sparks, flames, heat, or hot slag could be sources of ignition.
    20.1.4 Certified welders shall perform welding or flame cutting operations on surface facilities, piping, and equipment for which the primary function is to contain hydrocarbons.
20.4 Equipment
    20.4.1 Apparatus such as torches, regulators, hoses, and arc welding machines shall be in good operating condition and repair. Only approved oxygen and acetylene cylinders shall be used.
    20.4.2 Oxygen and acetylene torches should be equipped with flash-back arrestors.
    20.4.3 All cylinders with a water weight capacity of over 30 pounds shall be equipped with a valve protection cap, a collar, or recess to protect the valve. Valve caps shall be in place except when cylinders are connected for use.
    20.4.4 Cylinders shall be stored in assigned places away from elevators, stairs, or walkways. They shall be secured to prevent accidental overturning.
    20.4.5 Cylinders shall not be kept in unventilated enclosures, such as lockers and cupboards.
    20.4.6 Oxygen cylinders in storage shall be separated from fuel gas cylinders or combustible materials a minimum distance of 20 ft (6.1 m) or by a noncombustible barrier at least 5 ft (1.5 m) high.
    20.4.7 Acetylene cylinders shall be stored valve end up with protective caps affixed and properly secured. When a job using acetylene devices is completed or prior to transporting acetylene cylinders, the valve on the acetylene cylinder shall be closed and pressure on the hoses bled to zero.
    20.4.8 When transporting cylinders by a crane or derrick, a cradle, bin, or other suitable platform shall be used. Slings shall not be used. Also, cylinders shall not be dropped, struck, or permitted to strike each other.
    20.4.9 On arc welding machines, the control apparatus shall be enclosed except for the operating wheels, levers, or handles.
    20.4.10 Input power terminals, top charge devices, and electrically energized metal parts shall be completely enclosed and accessible only by means of tools.
    20.4.11 Terminals from welding leads shall be protected from accidental contact by personnel or metal objects.
    20.4.12 The frame or case of an electrically driven arc welding machine shall be grounded.
    20.4.13 Cables with splices within 10 ft (3.1 m) of the holder shall not be used. The welder should not coil or loop welding electrode cables around parts of his body.

20.5 Welding Fumes and Ventilation

    20.5.1 Toxicity depends on the composition and concentration of the fumes. The composition and quantity of fumes depends on the materials being welded, the composition of the welding rods, any coatings or paints encountered in the welding operations, the process used, and the circumstances of use. Toxic fumes can be generated from welding on metals coated with or containing alloys of lead, zinc, cadmium, beryllium, and certain other metals. Some paints and cleaning compounds may also produce toxic fumes when heated. The potential health effects range in type and severity, depending on these factors; and some effects can be extremely serious.
    20.5.2 For more information on the toxicity and health hazards of welding fumes and the appropriate protective measures, contact the employer, or consult the following references: Industrial Ventilation, A Manual of Recommended Practice, 22nd Edition1; Threshold Limit Values and Biological Indices for 1997–981; and API Publication 2201.
    20.5.3 Mechanical ventilation at the minimum rate of 2,000 ft3/min (94.4 dm3/s) per welder shall be provided when welding is done:
      a. In confined spaces or where the welding space contains partitions, balconies, or other structural barriers to the extent that they significantly obstruct cross ventilation.
      b. Where the nature of the welding, cutting, or brazing work is such that the release of toxic fumes or gases is possible. This includes work on stainless steel, zinc, lead, and degreasing or cleaning compounds containing hydrocarbons.

    20.5.4 Adherence to confined space entry procedures shall be followed prior to any re-entries. For example, releases from acetylene cutting equipment could change the atmosphere within the confined space.

Whenever metals are being welded together, hazardous fumes, gases, and sparks are generated. To establish a clean and safe working environment, it's crucial to understand and abide by welding safety and to utilize extraction systems wherever welding equipment is being operated.

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