Acetylene (C2H2) is a fuel gas that cannot be compressed directly as it explodes at high pressures. ("Oxyacetylene or Gas welding" 2015) Oxyfuel Gas Welding Outfit refers to the equipment needed in the welding process. Oxygen and Acetylene Cylinders are cylinders that come in various sizes and pressures that range from 2000- 2640 PSI which are made of solid armor plate steel and contains oxygen that will be mixed with acetylene to make the flame. Regulators serve the purpose of controlling the storage cylinder pressure so that the mixture of chemicals create the right amount of flame. Backfire is defined as the momentary deterioration of the flame into the torch tip which causes snapping or popping. Flashback is a momentary or sustained retrogression of the flame upstream of the mixer usually in the torch or hoses ("Backfires Flashbacks and Flashback Arrestors " 2004).