Figure 5-22.—Floor plan of a typical bathroom.
fitting) that leads to a 4-inch main house drain. The
vent pipe runs parallel to the floor drain, slightly
above the lavatory.
Figure 5-21, view B, is an isometric drawing of
the water pipes, one for cold water and the other for
hot water. These pipes are connected to service pipes
in the wall near the soil stack, and they run parallel to
the drain and vent pipes. Look back at figure 5-20 and
you can see that the water service pipes are located
above the drain pipe.
Figure 5-23 shows you how to read the designa-
tions for plumbing fittings. Each opening in a fitting
is identified with a letter. For example, the fitting at
the right end of the middle row shows a cross reduced
on one end of the run and on one outlet. On crosses
and elbows, you always read the largest opening first
and then follow the alphabetical order. So, if the fitting
has openings sized 2 x 1/2 by 1 1/2 by 2 1/2 by 1 1/2
inches, you should read them in this order: A = 2 l/2,
B = 1 1/2, C = 2 1/2, and D = 1 1/2 inches.
On tees, 45-degree Y-bends or laterals, and
double-branch elbows, you always read the size of the
largest opening of the run first, the opposite opening
of the run second, and the outlet last. For example,
look at the tee in the upper right corner of figure 5-23
and assume it is sized 3 by 2 by 2 inches. You would
read the openings as A = 3, B = 2, and C = 2 inches.
Figure 5-23.—How to read fittings.
5-17
