(1) Protective clothing made of cotton or wool should be worn to shield all parts of the body from the rays of the arc and from metal spatter.
(2) A helmet should be worn to protect eyes and face. See EYE PROTECTION.
(3) The operator should be insulated from the work-piece when changing electrodes.
(4)Noncombustible or fire-resistant screens should be provided to protect workers or other persons in the vicinity of the welding or cutting operation from the rays of the arc and weld spatter. Workers in the vicin- ity of the operations are required to wear eye and face protection, and protective clothing.
(5) Hot metal should be marked to remind shop personnel not to touch it.
(6) The frame or case of a welding machine should be connected to an earth ground. The workpiece lead connecting the work to the power supply should be made as short as possible.
(7) Combustible material should not be used to support the workpieces.
(8) Clear glass goggles should be worn to protect the eyes when removing slag or spatter.
(9) Power lines to welding machines should be run overhead and out of reach of anyone standing on the ground.
(10) Pipe lines, tanks or containers should not be welded until they have been properly cleaned. Specific procedures are contained in ANSI/AWS F4.1, Safe Practices for Preparation for Welding and Cutting of Containers and Piping.
(11) A fire extinguisher should be available during any welding operation. See FIRE HAZARDS AND PROTECTION.
Oxyfuel Gas Welding and Cutting
Cylinder Safety- Compressed gas cylinders are safe for the purposes for which they are intended. Serious accidents connected with their handling, use and storage can often be traced to mishandling or abuse. Only cylinders designed and maintained in accordance with specifications of the U.S. Department of Transportation (DOT) may be used in the United States. Cylinders must not be filled except by the owner, or with the consent of the owner, and then only in accordance with the regulations of the U.S. Department of Transportation. It is illegal to remove or change the numbers or marks stamped into cylinders. Proper names for gases should always be used. Oxygen should not be referred to as “air,” or acetylene as “gas.” Several safety rules are specific to oxygen and acetylene.
Oxygen- Oxygen is not flammable, but it supports combustion. Oil and grease should not be allowed to come in contact with oxygen cylinders, valves, regulators, gauges, or fittings. Oxygen cylinders or apparatus should not be handled with oily hands or gloves because spontaneous combustion may occur.
Neither oxygen nor any gas should be used as a substitute for compressed air to power pneumatic tools or similar devices. It is dangerous to use oxygen to start a diesel engine, for imposing pressure in oil reservoirs, for paint spraying, or for blowing out pipelines. Pressure from an oxygen or gas supply should never be used to clear clogged oil lines.
Acetylene- The cylinder valve should be fully open when the cylinder is in use. Acetylene should never be used at a gauge pressure in excess of 103 Kpa (15 psi). Acetylene cylinders should be used and stored in an upright position to avoid the possibility of drawing out acetone. The pressure in an acetylene cylinder does not accurately indicate the amount of gas contained in the cylinder. The amount is determined by weight.
High-pressure and Fuel Gas Cylinders
Gases used in oxyfuel gas welding, cutting, brazing, and heating operations are oxygen, acetylene, hydrogen, methylacetylene propadiene (MAPP), propylene, methane (natural gas), and propane.
The two main categories of cylinders used in these operations are high-pressure cylinders and fuel gas cylinders. The following rules apply to both these categories:
General Rules
(1) Regulators, pressure gauges, hoses or other apparatus provided for use with a particular gas must not be used on cylinders containing a different gas.
(2) Threads on regulators or other unions are designed to match those on cylinder valve outlets for specific gases. Connections that do not fit should not be forced.
(3) Attempting to mix gases in a cylinder, or attempting to transfer any gas from one cylinder to another, is prohibited.
(4) Never, under any circumstances, should the operator attempt to refill any cylinder.
(5) Tampering with safety devices on cylinders or cylinder valves is prohibited. Repairing or altering cylinders or valves should never be attempted.
(6) An open flame should never be used to detect combustible gas leaks. Soapy water should be used for this purpose.
(7) Connections to piping, regulators, and other appliances should always be kept tight to prevent leakage.
(8) Caps should be provided for valve protection; the caps should be kept on cylinders except when cylinders are in use.
Operating Safety
(1) Gases from cylinders should never be used without reducing the pressure through a suitable regulator attached directly to the cylinder.
(2) After the valve cap is removed, the valve should be opened for an instant to clear the opening of particles of dust or dirt.
(3) A pressure-reducing regulator should be attached to the cylinder valve before it is put in use.
(4)After attaching the regulator and before the cylinder valve is opened, the adjusting screw of the regulator must be released.
(5) The cylinder valve should be opened slowly, using only tools or wrenches provided or approved by the gas manufacturer. The gas should never be permitted to enter the regulator suddenly.
(6) Before a regulator is removed from a cylinder, the cylinder valve should be closed and all gas released from the regulator.
(7) The operator should not use the regulatorsattached to cylinders as brackets to hang torches.
(8) Sparks and flames from the welding or cutting torch should be kept away from cylinders.
(9) Hot slag should not be allowed to fall on combustible materials or on the cylinders.
(10) When cylinders are not in use, valves should be kept tightly closed.
Cylinder Storage
(1) Do not store cylinders near flammable material, especially oil, gasoline, grease, or any substance likely to cause or accelerate fire.
(2) Do not store reserve stocks of cylinders containing combustible gases with oxygen or other gases; they should be grouped separately.
(3) Store all cylinders in a well-ventilated place.
(4)All cylinders should be protected against excessive rise of temperature. Cylinders may be stored in the open, but in such cases, should be protected against extremes of weather. During winter, cylinders stored outdoors should be protected against accumulations of ice or snow. In summer, cylinders stored outdoors should be screened against continuous direct rays of the sun.
(5)Cylinders should not be exposed to continuous dampness.
(6) Full cylinders should not be stored near elevators or gangways, or in locations where heavy moving objects may strike or fall on them.
(7) Full and empty cylinders should be stored separately to avoid confusion.
Safe Handling
(1) Cylinders should never be dropped or permitted to strike each other violently.
(2) A lifting magnet, or a sling rope or chain should not be used when handling cylinders. A crane may be used when a safe cradle or platform is provided to hold the cylinders.
(3) Cylinders should never be used as rollers, supports, or for any purpose other than to carry gas.
(4)When empty cylinders are returned, cylinder valves should be closed before shipment. Protective caps and nuts for valve outlets should be in place before shipping empties.