Chapter 15 Oxyfuel Gas Cutting 415 Copyright Goodheart-Willcox Co., Inc. 5. Press or squeeze the cutting oxygen valve (lever). The preheating flames should remain neutral. If a carburizing flame is obtained, as shown in the following figure, open the torch oxygen finger valve a little more. Carburizing Flame Smith Equipment, Division of Tescom 6. Slightly adjust both the acetylene and oxygen torch valves until neutral preheating flames remain while the cutting oxygen valve is open. See the following figure. The torch is now adjusted and is ready to be used as a cutting torch. Without Cutting Oxygen Goodheart-Willcox Publisher With Cutting Oxygen Goodheart-Willcox Publisher Proper adjustment of cutting torch fl ames is a skill to be learned under the guidance of an experienced instructor. See Figure 15-11. American Welding Society Figure 15-11. An instructor showing a welder how to adjust the cutting torch flames. Note A cutting torch attachment has an extra cutting oxygen finger valve near the cutting oxygen lever (refer to Figure 15-3). When using a positive-pressure cutting torch attachment, one additional step is required to light the torch. Prior to performing the five steps above, open the cutting torch at- tachment’s oxygen valve one full turn. Then carefully follow the five steps as listed. After opening this cutting oxygen valve, make all oxygen adjustments at the torch oxygen valve on the torch body. In order to create clean and accurate cuts, the cut- ting tip must be in excellent condition and set to align properly with the cutting line. The preheating fl ames must be correctly adjusted, and the cutting oxygen pressure must be correct. To cut, bring the tip of the inner cone of the pre- heating fl ames to the edge of the metal to be cut. Hold the cutting torch so the inner cone of the preheat fl ames is about 1/16″ to 1/8″ (1.5 mm to 3 mm) from the surface of the metal being cut. See Figure 15-12.