Fig. 34.—Burning a Lap Seam on Round Pipe.
This seam is used almost exclusively on pipe in a vertical position, and is similar to the horizontal lap seam. The pipe is prepared by spreading the lower piece of pipe with a drift plug one size larger than the size of the pipe used. The end of the pipe intended to enter this socket is rasped to a bevel edge, as shown at a, Fig. 33. This end is then shaved clean, as is also the inside of the socket. The pipe is then placed into the socket, which is then dressed up tight against the inserted pipe, as shown in Fig. 34. The exposed edge is then cleaned and burned, as described for horizontal lap seams.
The Tee Joint on Round Pipe.
Fig. 35.—Making a Tee Joint on Round Pipe.
With a pair of compasses set the diameter of the pipe that it is desired to insert, and strike a circle on the pipe which is to receive the tee. With a tap borer, or any other device, cut out a circle of lead, leaving about ¼ inch to turn up. Then draw this remaining lead up by means of a bending iron and a heavy piece of iron, such as a chisel, as shown at B in Fig. 35, until the hole is large enough to receive the piece intended for it, the end of which should be beveled with a fine rasp, as shown at a. The lead should then be dressed back against the pipe, after which remove the piece and shave clean, and proceed to burn as described for the lap seam on round pipe, and as shown in Fig. 36. Care must be taken in dressing up the lead flange to dress it slowly so as to avoid weakening the lead.
Lining Tanks.
The lining of chemical tanks being the principal work of the chemical plumber, a description of how this work is done will probably be of some use to the beginner. In preparing lead sheets for a tank the sheets should be cut so as to give the most seams on the bottom, because of the greater ease in making them. In large tanks I find it convenient to put the bottom in first, cutting it to make an easy fit, and then the sides are put in. These are cut to allow ¾-inch lap on the bottom.
The lead sheets are laid on the floor, or some other smooth place, which has previously been swept clean, and then dressed out smooth. This can best be done by using the wooden dresser to take out the large wrinkles and then smoothing with a lead flap. This flap is simply a piece of sheet lead about 3 inches wide and 12 inches long, one end of which is drawn into a roll to fit the hand. Then mark the laps and bend them to the desired position. The under side of the lap should be shaved clean, as also the lead under the lap, to facilitate fusion.