414 Modern Welding 8. To light the torch, open the torch acetylene valve approximately 1/16 to 1/8 turn. Then, use a fl int lighter to ignite the acetylene. 9. Open the torch acetylene valve until the acety- lene fl ame jumps away from the end of the tip slightly and back again when the torch is given a shake or whipping action. An alter- nate method of adjusting the acetylene, after the torch is lighted, is to turn on the acetylene until most of the smoke clears from the fl ame. See Chapter 4 for illustrations of various conditions of the fl ame adjustment. 10. Next, open the torch oxygen valve and adjust it to obtain neutral preheat fl ames. Open the cutting oxygen valve by depressing the lever, and readjust the preheat fl ame if necessary. The neutral fl ame may be altered when the cutting oxygen valve is opened. See Figure 14-9. The torch is now adjusted and is ready to be used as a cutting torch. Proper adjustment of cutting torch fl ames is a skill to be learned under the guidance of an experienced instructor. See Figure 14-10. Procedure for Lighting an Injector-Type Oxyacetylene Cutting Torch Figure 14-11 shows typical gas fl ow through an injector-type oxyacetylene cutting torch. The following procedure is used to turn on the oxyacet- ylene cutting outfi t, purge the system, and light the torch: 1. Check the equipment to make sure all parts are in good operating condition. 2. Inspect the regulators. The adjusting screws of the regulators should be turned all the way out (closing the regulator). 3. Standing to one side of the regulator, very slowly open the oxygen cylinder valve until the regulator high-pressure gauge reaches its maximum reading. Then, turn the cylinder valve all the way open. 4. Using an acetylene cylinder wrench, slowly open the acetylene cylinder valve 1/4 to 1/2 turn. Leave the wrench in place on the acety- lene cylinder valve. 5. Open the torch oxygen valve 1/4 turn. Open the torch oxygen cutting orifi ce lever wide A B Figure 14-9. Cutting fl ames. A—Without cutting oxygen. B—With cutting oxygen. Figure 14-10. An instructor showing a welder how to adjust the cutting torch fl ames. (American Welding Society)