*Welding in confined spaces *is intended to mean welding in a relatively small or restricted space such as a tank, boiler, pressure vessel, or small compartment of a ship or tank.
When welding or cutting is being performed in any confined space, the gas cylinders and welding machines shall be left on the outside. Before operations are started, heavy portable equipment mounted on wheels shall be securely blocked to prevent accidental movement.
Where a welder must enter a confined space through a manhole or other all opening, means will be provided for quickly removing him in case of emergency. When safety belts and life lines are used for this purpose, they will be attached to the welder’s body so that he cannot be jammed in a small exit opening. An attendant with a pre-planned rescue procedure will be stationed outside to observe the welder at all times and be capable of putting rescue operations into effect.
When arc welding is suspended for any substantial period of time, such as during lunch or overnight, all electrodes should be removed from the holders with the holders carefully located so that accidental contact cannot occur. The welding machines should be disconnected from the power source.
In order to eliminate the possibility of gas escaping through leaks or improperly closed valves when gas welding or cutting, the gas and oxygen supply valves will be closed, the regulators released, the gas and oxygen lines bled, and the valves on the torch shut off when the equipment will not be used for a substantial period of time. Where practical, the torch and hose will also be removed from the confined space.
After welding operations are completed, the welder will mark the hot metal or provide some other means of warning other workers.