Electrical Welding
Welding cable shall be connected in an approved manner. There shall be no exposed metal parts in any splice. Welding cable shall be inspected regularly. Splices shall be avoided.
The ground cable shall be attached as close as possible to the work piece by means of a clamp. The ground cable shall not be attached to an existing installation or apparatus.
Welding of the ground cable is forbidden.
Welding equipment shall be installed so that it can be seen by the welder during welding activities. Welding equipment may not be placed in the path of falling sparks.
Cables shall be kept clear from passageways, ladders and stairs. When potentially subject to damage, cables shall be protected by suitable covers.
When not in use, diesel welding machines, generators and transformers shall be switched off. When in use, they shall be protected by suitable covers and barricaded.
Hot electrode holders shall not be dipped in water. This may expose the welder to electrical shock.
Welding equipment shall be inspected regularly in accordance with the manufacturer’s specification and the EPC Contractor’s requirements.
Gas Welding and Burning
Welding or cutting torches and hoses shall not be connected to cylinders when stored. Cylinders must always be secure so that they cannot be tipped over or otherwise fall. Cylinders shall not be placed in containers or buildings. When work is stopped and equipment is unattended, all valves at the gas and oxygen cylinders shall be closed. The hoses shall be bled and a check shall be made five minutes later for possible pressure build-up. Torches shall be removed from the hoses prior to putting them into the toolbox. Smoking isnot permitted anywhere near gas cylinders.
Special care shall be taken during overhead cutting and welding operations to safeguard and prevent falling sparks from starting a fire. Warning signs shall be posted around and at each level below the area of each overhead welding or burning operation. Fire extinguishers shall be available and fire blankets shall be used for protection.
When welding or cutting, adequate ventilation must be furnished.
Hoses shall be kept clear from passageways, ladders and stairs. When hoses are subject to damage, they shall be properly protected. Hoses shall be inspected regularly.
The use of full or empty cylinders as supporting elements for welding activities is forbidden.
Compressed Gas Cylinders
Compressed gas cylinders shall be upright when in use, secured to prevent falling, and protected from flame and extreme heat and from being struck by moving equipment and falling objects. Special wrenches must be provided for securing fittings.
If transported by crane, hoist or derrick, compressed gas cylinders shall be handled in a suitable cradle, net or skip box, never by wire or fiber rope, web or chain sling, nor by dragging. Regulators shall be removed and protective valve caps placed prior to hoisting.
Oxygen cylinders may never be stored near highly combustible materials, especially oil and grease, or near compressed fuel gas cylinders. Oxygen and fuel gas cylinders in storage shall be separated by a distance of 6 meters or by a wall 2 meters high made of fire-resistant material.
Caps shall be replaced on cylinders that are empty, and such cylinders shall be stored separately in a section clearly designated for empty cylinders.
Gas and oxygen cylinders shall not be taken into confined spaces or be placed on scaffolds.
Check valves shall be used immediately behind the reducing vent on acetylene cylinders.
Gas and oxygen cylinders shall only be used when secured on a cylinder carrier. Loose cylinders shall never be used.
15.30 Explosion and Gas Hazards
No work involving a source of ignition shall be attempted near any pit, manhole, open sewer, drain vent, pipe trench or any enclosed space where there is reason to believe that flammable vapors may be present, until tests have been made with an approved hydrocarbon vapor detector and oxygen detector. When said tests indicate the atmosphere is safe, work may proceed.
At locations similar to the ones above, where there is reason to believe that toxic gas may be present, similar tests with an approved toxic gas detector and oxygen detector shall be made. No work shall be performed in the location until said tests indicate toxic gas concentrations lower than the maximum permissible.