Do not use cheaters or pipes. Cylinders that do not have fixed handwheels will be equipped with keys, handles or nonadjustable wrenches on the valve stems during the time they are in service. Before removing a regulator from a cylinder, close the control valves and allow the gas to escape from the regulator. Welders shall not leave an area with regulators or lines pressurized. On oxygen cylinders, do not use a regulator that has been previously used for oil-pumped gases or any combustible gases.
Acetylene is a colorless, flammable gas with a distinctive garlic-like odor.
A mixture of this gas with oxygen or air in a confined area will explode when brought in contact with a flame or other source of ignition. A pressure-reducing regulator must be used when drawing acetylene from a cylinder. Never adjust the regulator to obtain a delivery pressure greater than 15 psig. Under certain conditions, acetylene forms readily explosive compounds with copper, silver and mercury. Contact should be avoided between acetylene and these metals, their salts, compounds and high-concentration alloys.