Oxygen-Fuel Gas Welding & Cutting General Requirements

Mixtures of fuel gases and air or oxygen may be explosive, and employees must be protected from this hazard. No device or attachment facilitating or permitting mixtures of air or oxygen with flammable gases prior to consumption are allowed unless approved for the purpose, except at the burner or in a standard torch. Cylinders used to power hot work must be placed where they cannot become part of an electrical circuit. Electrodes must not be struck against a cylinder to strike an arc.

Under no circumstances is it acceptable for acetylene to be generated, piped (except in approved cylinder manifolds), or utilized at a pressure in excess of 15 pounds per square inch gauge (psig) or 30 pounds per square inch absolute (psia). The use of liquid acetylene is prohibited.

When the valve on a fuel gas cylinder is opened, if there is a leak around the valve stem, the valve must be closed and the gland nut tightened. If this does not stop the leak, the use of the cylinder must be discontinued, and it must be properly tagged and removed from the work area. In the event that fuel gas should leak from the cylinder valve, rather than from the valve stem, and the gas cannot be shut off, the cylinder must be properly tagged and removed from the work area. If a regulator attached to a cylinder valve will effectively stop a leak through the valve seat, the cylinder does not need to be removed from the work area.

Only approved equipment such as torches, regulators or pressure-reducing valves, acetylene generators, and manifolds are acceptable for use during oxygen-fuel gas welding. All welding cables and other equipment must be placed so that they are clear of passageways, ladders, or stairways.

Operators in charge of the oxygen or fuel-gas supply equipment, including generators, and oxygen or fuel-gas distribution piping systems, must be instructed and judged competent by their employers for this important work before being left in charge. Rules and instructions covering the operation and maintenance of oxygen or fuel-gas supply equipment including generators, and oxygen or fuel-gas distribution piping systems must be readily accessible.

When gas welding or cutting in confined spaces, the torch valves must be closed and the gas supply to the torch shut off at a point outside the confined area whenever the torch is not to be used for a substantial period of time, such as during lunch breaks or overnight. If possible, the torch and hose must also be removed from the confined space.

Clogged torch tips must be cleaned with suitable cleaning wires, drills, or other devices designed for cleaning clogs. Before use, torches must be inspected at the beginning of each working shift for leaking shutoff valves, hose couplings, and tip connections. Defective torches must not be used. Torches must be lighted by friction lighters or other approved devices, and not by matches or from hot work.

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