Chapter 15 Oxyfuel Gas Cutting 411 Copyright Goodheart-Willcox Co., Inc. an oxyacetylene welding outfi t and checking for gas leaks in the regulators, cylinder-to-regulator connec- tions, hoses, and hose fi ttings, which can be found in Chapter 13, Oxyfuel Gas Welding. 15.3.1 Cutting Torch A cutting torch is similar to a welding torch how- ever, a cutting torch has a separate passageway for the oxygen jet. As in welding, the positive-pressure cutting torch is connected to oxygen and fuel gas cylinders. In an oxyfuel gas cutting torch, the preheat- ing flames come from one or more of the torch tip’s orifices arranged around a central oxygen orifice. The welder controls the cutting operation using the cutting oxygen lever. See Figure 15-3. In operation, a preheating flame is maintained at the tip through small orifices arranged around the cutting oxygen orifice. Cuts are made by depressing the cutting oxygen lever on the torch, which operates a cutting oxygen valve inside the torch, to control the flow of oxygen from the center orifice. See Figure 15-4 and Figure 15-5. Cutting oxygen valve Cutting oxygen lever Uniweld Products, Inc. Figure 15-3. A standard cutting torch attachment that quickly attaches to a torch body. Cutting oxygen Mixing chamber Cutting oxygen lever Cutting oxygen valve ESAB Welding and Cutting Products Figure 15-4. A cross-sectional drawing of cutting torch with the preheat gas mixing chamber in the torch body. Stainless steel ball-type valves Torch body Cutting oxygen lever Cutting oxygen valve Oxygen torch valve Check valve Stainless steel tubes Replaceable seats in tip Cutting tip Gases mix in tip Tip nut Fuel gas Oxygen Smith Equipment Figure 15-5. A sectioned view of cutting torch attachment mounted on a torch body. The preheat gases are mixed in the tip of the torch where it connects into the torch head.