that are ¾″ or more in width. Stacks should be set in concrete at their base and secured to the building frame in order to maintain alignment. (Additional information about pipe supports is provided toward the end of this chapter.) ABS pipe and fittings were developed in the early 1950s and originally used in oil fields and the chemical industry. John F. Long, an Arizona builder, is credited with the first use of ABS pipe and fittings in residential plumbing in 1959. Choose the appropriate solvent cement for the type of plastic, Figure 19-29. Using the swab that is attached to the solvent cement cap, apply a light coat of the cement to the fitting socket. Do not use the same swab to apply cleaning solvent and solvent cement. Next, apply a heavy coat of cement to the pipe end. See Figure 19-30. Immediately insert the pipe all the way into the fitting socket while giving it a quarter turn, Figure 19-31. This rotation assures that the solvent cement is evenly distributed in the joint. A small bead of solvent cement should be visible completely around the fitting. This indicates that the proper amount of cement was applied. No bead or a partial bead may indicate incom- plete bonding that could result in a leaking joint. The solvent cement will set up in two to five minutes and can be handled with care at that time. Allow 24 hours setting time before testing the pipe. Supporting Pipe Horizontal runs of plastic pipe should be supported every 3′–4′ with metal or plastic hangers Goodheart-Willcox Publisher Figure 19-28. Using a miter box assures a square cut on plastic pipe. Goodheart-Willcox Publisher Figure 19-29. Various types of solvent cement are available for making joints in plastic piping. Type of plastic Cement ABS CPVC PVC ABS dissolved in methylethylketone CPVC dissolved in tetrahydrofuran PVC dissolved in tetrahydrofuran Goodheart-Willcox Publisher Figure 19-30. Apply solvent cement to plastic pipe with brush or dabber. Goodheart-Willcox Publisher Figure 19-31. Turn the pipe ¼ turn as the joint is assembled and hold it in position until the cement has set. Chapter 19 DWV Pipe and Fitting Installation 315 Copyright Goodheart-Willcox Co., Inc.