Page 193 - Trenchless Technology Piping Installation and Inspection

158 Cha pte r F o u r

From a design perspective, both solid wall and profile wall PVC-
gravity pipes are limited to a vertical deflection of 7.5 percent, per
ASTM and Uni-Bell recommendations. For pressure pipe, AWWA
M45 “Fiberglass Pipe Design” Manual recommends a deflection limit
of 5 percent.
Generally, profile wall pipes are used for open-cut installations as
well as trenchless renewal processes such as sliplining. Pipes used for
sliplining have modified joints that facilitate their installation by seg-
mental sliplining.

PVC Applicable Standards and Products for Trenchless Construction
Although there are several widely used bell-and-spigot gasket-joint
PVC pressure and gravity piping standards in North America written
by organizations such as AWWA, ASTM, and CSA, products dis-
cussed in this chapter are specifically for trenchless applications.
They are proprietary in nature in that they have uniquely designed
jointing systems that enable the pipe to be pulled or pushed for vari-
ous trenchless construction methods (TCMs). Table 4.10 outlines
details on each product along with pictures of joints. Also, there are
several types of PVC piping products geared toward use in trenchless
renewal market. Typically, these are profile wall pipes with proprie-
tary joints. Information on these products is not included in this
chapter but more details may be obtained from manufacturers or
Uni-Bell PVC Pipe Association. Table 4.10 presents a summary of
PVC pipe standards and joint systems.

1. Fusible C-900™, Fusible C-905™, and Fusible PVC™: Until
recently, PE was the only available thermoplastic pipe option
that used butt-fused joints in the United States, and this was
the case for well over 30 years. In the late 2003, the water or
wastewater industry saw the introduction of Fusible PVC,
or Fusible C-900, or Fusible C-905. A first of its kind, this
product combines a proprietary formulation and fusion pro-
cedure that allows lengths of PVC pipe to be joined together
in a continuous string for installation through a variety of
methods, including HDD, sliplining, pipe bursting, and direct
bury applications. Although Fusible PVC is primarily for
nondrinking water applications like recycled water, force-
mains, gravity drains, and sewer applications, Fusible C-900
or Fusible C-905 are specifically for use in potable water
systems. The pipes are manufactured to all requirements of
AWWA C900 and C905, and are National Science Foundation
(NSF) certified. Surface scratches of up to 10 percent of the
pipes’ outside diameter are accepted, per AWWA, during
pull-in of all PVC pipes. A major advantage of the fusible
pipe is that those municipalities already using conventional
PVC can now use the same material in trenchless construction,