Through Seam on Round Pipe.
Where heavy pipe that is to be used under pressure is to be joined it must be burned through to provide strength, and the ends prepared in the same way as just described, but the ends must also be trimmed off all the way around with a slight bevel reaching from the outside almost to the inside bore of the pipe. The bevel must stop so as to allow a narrow square butt end on each pipe. Then when a piece of paper has been placed on the inside to prevent lead running into the pipe, the two ends when butted will present a V-shaped groove, as shown in Fig. 32, reaching all around the pipe. The burning is commenced at the bottom, as shown in Fig. 31, and the two ends securely united. The groove is then filled by burning on additional lead from a thin cleaned strip until the groove is filled and the pipe made as heavy and strong at this point as anywhere on its entire length.
Fig. 32.—Joint Prepared for Through Burning.