745 Welding, Cutting, and Brazing Safety

Operating Gas Welding Equipment

• Keep the valves closed on empty cylinders.
• Do not stand in front of cylinder valves while opening them.
• When a special wrench is required to open a cylinder valve, leave the wrench in position on the valve stem while using the cylinder so you are able to close the valve quickly in an emergency.
• Keep oxygen cylinders and fittings away from oil and grease. Even a small amount of oil or grease may ignite violently, with explosive force, in the presence of oxygen.
• NEVER lubricate any part of an oxygen cylinder, valve, or fitting.
• Do not drop cylinders. Do not handle them roughly. Rough handling may cause a cylinder valve to break off, and the sudden release of gas from a full cylinder may cause it to take off like a rocket.
• Always open cylinder valves slowly. (Do not open the acetylene cylinder valve more than 1 1/2 turns.)

• Close cylinder valves before moving cylinders.
• Never attempt to force unmatching or crossed threads on valve outlets, hose couplings, or torch valve inlets. The threads on oxygen regulator outlets, hose couplings, and torch valve inlets are right-handed; for acetylene, these threads are left-handed. The threads on acetylene cylinder valve outlets are right-handed but have a pitch that is different from the pitch of the threads on the oxygen cylinder valve outlets. If the threads do not match, the connections are mixed.
• Always use the correct tip or nozzle and the correct pressure for the particular work involved. You can get this information from tables or worksheets supplied with the equipment.
• Do not allow acetylene or acetylene and oxygen to accumulate in confined spaces. Such mixtures are highly explosive.
• Keep a clear space between the cylinders and the work so you can reach the cylinder valves quickly and easily if necessary.
• Open the acetylene valve first and ignite the gas while the oxygen valve is closed when lighting the torch.
• Do not allow unburned acetylene to escape and accumulate in small or closed compartments.
• Close the acetylene valve first and then close the oxygen valve when extinguishing the torch.

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