Figure 3-10.Adapter-type cast-iron soil pipe fittings.
feet apart in horizontal 4-inch building drain lines in a
straight run. When the change of direction is greater
than 45 degrees (or a 1/8 bend), you must install a
The long hub, or Sisson, type of cleanout (view B,
fig. 3-10) is used as an insert to an existing line. The
long hub allows you to push it up far enough to clear
the other bell of the bottom pipe, and then to drop the
fitting in place.
Another type of adapter is a sewer thimble (or
saddle). This is a special fitting that is used to tie into an
existing sewer line, as shown in view C, figure 3-10. It
has a hub on one end, bending around to almost 45
degrees, with a flange near the opposite end. To install,
cut a hole halfway between the top and the center line
in the sewer line. The hole should be the same size as
the outlet portion of the thimble beyond the flange.
Slip the thimble into the opening until the flange seats
on the sewer pipe. Using oakum and concrete, grout
around the thimble to make a watertight joint.
The increaser (fig. 3-11) is used to increase the size
(diameter) of a straight-through line. It is often used at
the top of a main stack and vent.
A closet bend (fig. 3-12) is a special fitting inserted
into a soil branch. This enables the soil branch to be
fitted to the water closet. It may be untapped or have
either one or two side taps for waste to vent use. Closet
bends are made in different styles to fit different types
of floor flanges (rims for attachment). One type (view
A, fig. 3-12) has a spigot end for caulking into the
branch line, and a scored end (marked with lines) to fit
into the floor flange. The scoring makes it easier to cut
the bend to the desired length for a given connection.
Another type, shown in view B, figure 3-12, has a hub
connected to the floor flange with a sleeve or short
length of pipe. The end caulked into the soil line is
scored for cutting to size. Still other types may be
scored for cutting at both ends or may be of the regular
Regular offsets, view A, and 1/8 bend offset, view
B, figure 3-13, are used to carry the soil or waste lines