All cutting and welding operations performed at Tufts by Tufts personnel or contractors must be carried out in accordance with standards set forth by the American Welding Society and the appropriate American National Standards Institute (ANSI) standards concerning cutting and welding.
Cutting and welding is permitted only in designated areas. These areas are used for routine operation of a shop or laboratory that has been approved by the Fire Marshal’s Office.
Cutting and welding outside of these areas is not permitted within any Tufts building without a Hot Work Permit issued by the Fire Marshal. The permit shall be obtained at least 24 hours in advance of the work to be done, except in an emergency situation. (Failure to obtain a permit is not considered an emergency).
When cutting or welding outside a designated area, remove the work to a safe location free of combustible materials if possible. If the work cannot be moved, clear flammable materials and rubbish from the area for about a 35′ radius. If these precautions are not feasible, shield or cover such materials with fire resistive materials to protect them for combustion. Holes in the floor and walls must be covered to prevent sparks from falling through unnoticed onto people or combustible materials below.
Maintain a fire watch when doing this kind of work and have a charged fire extinguisher readily available. Depending on the job, more than one fire watch may be needed on the other side of a wall or floor that a pipe passes through, to control potential ignition from sparks or conduction. Check the area for 30 minutes to 1 hour after stopping work for the day to make sure no smoldering materials exist. Most welding fires break out long after the operation has ceased, as they are caused by unnoticed sparks which travel long distances before lodging in combustible materials.
Do not cut or weld any closed vessel that has contained or is suspected to have contained flammable or toxic materials until it has been tested, thoroughly cleaned, purged and vented. Traces of the material may still be in the vessel and result in a fire or explosion, or create a toxic exposure.
When welding or using a torch, wear lenses for filtering harmful radiation. Gloves and aprons of leather or other insulated materials and other appropriate protective clothing shall be worn. Always wear some sort of covering to protect your hair from sparks. Nylon and other synthetic fibers are not recommended, because sparks coming in contact with them can cause serious burns from the melting fabric. Wear high-cut shoes and avoid wearing pants with cuffs to prevent sparks from entering either.
Toxic Fumes and Gases
Many cutting and welding operations produce toxic fumes and gases. If you have to cut or weld materials or use fluxes containing fluorine compounds, zinc, lead, beryllium, cadmium, mercury or other toxic materials, special ventilation and respiratory protection will be needed. Consult with the Occupational Safety Officer at the Environmental Health and Safety Office.
In case of an injury, contact the Tufts Police immediately and provide emergency first aid to the victim until help arrives. Personnel working with electrical welding machine should know C.P.R.; contact Tufts Police for training information.
Gas Cutting or Welding
Store oxygen and acetylene cylinders in specifically assigned locations where they will not be knocked over or damaged by chaining them securing into place. If stored outside, protect from snow accumulations and from direct sunrays.
Oil and grease in the presence of oxygen may ignite with explosive violence. Do not use oil, grease or other readily oxidizable substances on any regulator or torch. Do not handle this equipment with oily rags or gloves.
Keep cylinders away from sources of heat such as radiators and from contact with electric circuits. Cylinders must be kept far enough away from the cutting and welding operation to be exposed to the sparks and hot slag from the work.
Oxygen cylinders in storage must be separated from fuel gas cylinders or combustible materials by a minimum distance of 20 feet or by a noncombustible barrier at least 5 feet high having a fire resistance rating of at least one-half hour. Acetylene cylinders must be kept in the upright position and must never be used at a pressure of 15 pounds per square inch. Never use acetylene from cylinders without reducing the pressure through an approved regulator.
Always keep the key or wrench of the acetylene cylinder valve on the cylinder while in use. Never open an acetylene cylinder valve more than one full turn, this will aid in its quick closing in the event of an emergency. When finished with all work, shut-off the cylinder valve first, this will burn off the remaining gas in the lines and then keep the valve close even when empty. Keep the cylinder caps in place when the cylinders or being moved or stored.
Do not use oxygen to blow out pipelines or to dust off work or clothing.
Hose and power cables must be placed as to protect them from damage, hot slag and sparks. Do not leave them across corridors and walkway causing a trip hazard. Examine hoses and cables for damage, worn areas and leaks regularly. Do not use tape for repairs.
Cylinders must be transported on a handcart and chained in place. Cylinders should not be handled roughly or dropped.
The secondary of the supply transformer and case of any portable welding transformer, as well as the frame, must be grounded.
Electrode holders, when not in use, must be placed in such a manner that they cannot make electrical contact with people, other objects, fuel or compressed gas cylinders.
No cables may be used where splices are within 10 feet of the electrode holder. Do not coil or loop electrode-welding cables around parts of your body. Do not stand in water or on damp ground when doing electrical welding. Moisture connects your body to ground and may form the path of least resistance, causing a severe shock.
Gas-Shield Arc Welding
All gas-shield arc welding must be done in accordance with the recommended safe practices developed by the American Welding Society.
Common sense and safe working practice is the key to accident prevention. If you are unsure about an operation, request assistance
Contact the Tufts University Fire Marshal’s Office at 419 Boston Ave, Medford Campus, 617-627-3922 if you have any question.
Thank you for your assistance with making Tufts a safer place to work!