residential interior systems.
Cold-water service piping is usually
found in two ratings: 160 psi at 73°F and
250 psi at 73°F. Interior tubing carries a
rating of 100 psi at 180°F.
The most popular interior sizes are 1/2
inch and 3/4 inch. Manifold or "homerun"
systems (see "Home-Run Holds
Promise," page 41) use 1/2 or 3/8-inch tubing.
Cold-water service sizes are available
from 3/4
inch to 2 inches,
with 1 inch
the most popular.
Three types
of fittings are
available in a
variety of materials.
Insert fittings
are made
of copper or brass. Heat-fusion fittings
are made of PB. Compression fittings
may be made from Noryl, a polymer
made by GE Plastics, or Udell, also a
polymer, made by Amoco Chemical Co.
Manifolds that distribute