Cutting PVC and
CPVC Pipe
Plastic water supply pipe is cut with plastic
pipe cutters. The cut must be square so that a
full joint can be made with the socket. All burrs
on the cut end of the pipe should be removed
with a reamer or abrasive paper.
Joining PVC and CPVC Pipe
Joining plastic pipe is described in more
detail in Chapter 19. The following is a review of
the process.
1. Apply a solvent to both the pipe and fitting or
use abrasive paper to clean the pipe and
remove the gloss for better bonding.
2. Apply a light coat of the appropriate solvent
cement to the fitting socket with the swab
attached to the inside lid of the container. Do
not use the same brush/swab to apply the
cleaning solvent.
3. Apply a heavy coat of cement to the pipe
spigot.
4. Immediately insert the pipe all the way into
the fitting socket while giving it a quarter turn.
The rotation assures that the solvent cement
is evenly distributed in the joint.
A bead of solvent cement completely
around the fitting indicates that the proper
amount of cement was applied. No bead or a
partial bead may indicate incomplete bonding
that results in a leaking joint.
The solvent cement sets in two to five min-
utes and can be handled with care at that time.
Allow 24 hours before testing the pipe.
Supporting PVC and
CPVC Pipe
Horizontal runs of plastic pipe should be
supported with plastic hangers as indicated in
Figure 20-16. Screws can be used to fasten the
hangers to wood framing members. Concrete
anchors are required to secure pipe to founda-
tion walls. Additional information about pipe
supports and concrete anchors is provided in
Chapter 21.
Installing Copper
Pipe and Fittings
Installing copper water pipe and fittings is,
in many ways, similar to installing PVC and
CPVC water lines. The major difference is that
the joints are soldered rather than being joined
with adhesive. Before describing fabrication
techniques for copper pipe and fittings, the
problem of thermal expansion and contraction
is discussed so that any necessary modifica-
tions can be incorporated into the piping
system before the joints are soldered.
Thermal Expansion and
Contraction
Thermal expansion and contraction of
copper can be calculated using the same
362
Section 3 Plumbing System Design and Installation
Figure 20-16. The recommended maximum distance
between supports for PVC and CPVC.
Size PVC CPVC
1⁄2 4 3
3⁄4 4 3
1 41⁄2 3
Pipe Support Spacing (ft.)
Copper became a popular material for
plumbing in the 1930s following the develop-
ment of manufacturing techniques that pro-
duced thin-walled copper tube that is still in
use today. Before the 1930s, copper pipe had
thick walls, like galvanized and black iron pipe,
and was joined with threaded connectors.
History Brief