This pipe comes in about 18-foot lengths and fittings of the following makes and shapes, and their use is fully explained. The lengths of pipe come with a thread on each end and a coupling screwed on one end. The lengths come in bundles up to 11⁄2-inches and in single lengths over that size. Screw pipe fittings, it will be noted, are called by a different name than cast-iron ones. The fittings in common use today are the 90 degree ell, 45, 22, and 162⁄3. The Y and TY, tucker fittings, and inverted Ys are used in practically the same way as the cast-iron fittings. The 90 degree ell, 45, 22, and 162⁄3 are used to change the run of pipe that many degrees. All 90 degree fittings, ells, and Ts are tapped to give the pipe a pitch of 1⁄4 inch to the foot. It is better to use two 45 ells to make a 90 bend when it is possible.

CAST IRON SCREW FITTINGS Fig. 54. CAST-IRON SCREW FITTINGS Fig. 54.

Inverted Y

The inverted Y is used in venting to good advantage. The use of these fittings is illustrated in the sketches.

Waste Pipes

Waste pipes are the pipes that run to or convey the discharge of waste matter to the house drain, from wash trays, baths, lavatories, sinks, and showers.

The usual size of waste pipes is 2 inches. Waste pipes are made of the same material as soil pipe. Lead and brass pipe are also in common use. All exposed waste pipes in bath and toilet rooms are brass, nickel-plated. The waste pipes under kitchen sinks and wash trays are either lead or plain heavy brass. All waste pipes are run with a pitch towards the house trap and should be properly vented as explained under venting. The pipes should be easy of access, with clean-outs in convenient places. The waste pipes under a tile or cement floor should be covered with waterproof paper and a metal V-shaped shield over the entire length. If the waste pipes are over a decorated ceiling they should be in a copper-lined or lead-lined box. This box should have a tell-tale pipe running to the open cellar with the end of the tell-tale pipe left open. If waste pipes are to take the discharge from sinks in which chemicals are thrown, either chemical lead or terra-cotta pipe should be used. If terra-cotta is used, it should have at least 6 inches reinforced concrete around it and the joints of pipe made of keisilgar.