Safety in Gas Welding & Cutting – Using Caution with Gases Can Save Lives
Gas welding, cutting and heating apparatus are extremely useful tools for a variety of work and hobby applications. But Paul Mercuri of ESAB explains why any procedure that uses oxygen or other flammable gases in the presence of flame carries significant risks. He warns that every worker, from beginner to seasoned professional, needs to be constantly mindful of safety precautions.
Posted: August 24, 2009
Always follow proper procedures when using oxygen regulators:
Use only Oxygen regulators designed for oxygen service. A pressure reducing regulator must be connected to the oxygen cylinder valve. This regulator must be properly rated for the service pressure. Before installation, make sure the regulator is clean, free of grease and oil, and has a clean filter installed in its inlet nipple. Never use an oxygen regulator for other gases. Never connect a regulator that has been in non-oxygen service to oxygen service.
Before opening an oxygen cylinder valve make sure the oxygen regulator pressure-adjusting screw is released. This is done by rotating the screw counterclockwise until it turns freely. This closes the regulator valve and prevents damage due to a sudden pressure surge.
“Crack” the oxygen cylinder valve before attaching the regulator. Stand to one side of the cylinder outlet. Open the cylinder valve slightly for an instant, and then close it. This will clean the valve of dust and dirt which may have accumulated during storage.
When opening the oxygen cylinder valve, stand by the cylinder valve side of the oxygen regulator. Never stand facing the pressure adjusting screw or pressure gauges of the regulator while opening the cylinder valve. Open the cylinder valve as slowly as possible, until the high pressure gauge reaches cylinder pressure. Never open a cylinder valve suddenly. Sudden surges of high pressure can cause an oxygen regulator fire.
FUEL GASES
Oxygen is not the only gas you might use in a welding or cutting application. Fuel gases can also explode in air or oxygen if ignited by a flame, spark or other ignition source. Fuel gas can also cause rapid suffocation without warning. Acetylene, natural gas (mainly methane), and liquefied petroleum (LP) gases, such as propane, butane, propylene (FG-2, etc.) and MAPP are commonly used gases in gas welding, cutting and heating processes. These gases can displace the oxygen required for normal breathing. An atmosphere with less than 18 percent oxygen can cause rapid dizziness, unconsciousness or even death. Therefore, make sure a confined area is well ventilated before entering.
Never bring gas cylinders into confined areas or store gas equipment in confined areas when not in use. Never release fuel gas where it might cause a fire or explosion. Fuel gases should never be released into the air near other welding or cutting work, near sparks or flame caused by other means or in confined spaces. Sparks from circuit breakers, thermostats, etc. can cause ignition. If it is necessary to release fuel gas, release it outdoors.
Call fuel gases by their proper names ? not just ?gas.? Fuel gases differ from each other in heat content, flammability limits, handling characteristics and safe handling requirements. Know which gas you are dealing with and be specific when you refer to a particular fuel gas.
Everyone in your shop should know standard safety protocols, even if the worker is not directly involved with welding and cutting. Use of safety posters and warning devices, clear labeling of oxygen and gases, and taking the time to educate all workers about safety issues are all worthwhile endeavors to save lives and prevent injuries.
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