Corn pound Patch

material should be cut so it extends at least 2 inches on either side of the gap and should be long enough to provide one complete turn around the pipe with a pos- sible overlap of about 2 inches. Secure the substitute material with the chalk line. 2. Cut the woven roving cloth so it extends at least 4 inches beyond the edges of the bridge material. Im- pregnate the cloth with the resin/hardener mixture. Wrap the cloth around the bridge materials and tie it securely as you did for the simple pipe patch. 3. Apply the PVC film and tie it securely with the chalk line as you did for the simple pipe patch. Corn pound Patch.— When you are making re- pairs resulting from battle damage to piping systems, the compound-type rupture, as shown in figure 2-29, is the one you get most often. Since compound rup- tures may take a variety of shapes, it becomes difficult to select a single example to fit all repairs. In most compound ruptures, it should be possible to simplify the rupture by removing butterfly edges or by cutting away the damaged section to form either a severed pipe or a simple pipe repair. When the butterfly edges or other projections cannot be removed by pounding in, cutting, or burning, a simple pipe patch may be applied with the following modifications: 1. Tie the chalk line firmly between the jagged edges (view B of fig. 2-29) crisscrossing as much as possible. This chalk line acts as a support for the woven roving cloth and keeps it from falling into the void. No void cover is used in this example as it would be impractical to cut a void cover to suit the jagged edges shown in view A of figure 2-29. 2. A small piece of impregnated woven roving cloth (view C of fig. 2-29) is folded and laid in the void where it helps to build up the mass and acts as an insulator. 3. Apply the woven roving cloth (view D of fig. 2-29) cut to the appropriate length and width over the small folded piece of woven roving cloth, and tie it firmly as outlined previously for the simple pipe patch. Flange Patch.— The flange patch (fig. 2-30) is also applied similarly to the simple pipe patch, but it has some modifications in the application procedure. 1. As illustrated in view B of figure 2-30, the void cover is cut into an H shape, impregnated with the resin-hardener mixture, inserted into the void, and tied securely in place. Figure 2-29.—Compound rupture patch, edges not removed. 2. Four pieces of woven roving cloth are cut long enough to make one complete turn around the pipe and overlap 1 inch. These four pieces of woven roving cloth are cut in an H shape, but the center pieces are not cut away. Instead, they are folded up over the edges of the flange. 3. Impregnate the separate pieces of woven roving cloth with the resin-hardener mixture and place over the rupture, as shown in view C of figure 2-30. 4. Apply the PVC film and tie down firmly, start- ing at one end and working up to the flange. Make several windings through the gap in the flange in the 2-20