Page 187 - Trenchless Technology Piping Installation and Inspection

152 Cha pte r F o u r

Sleeve Sealing element
Sleeve may be (may have (may be affixed or recessed
affixed to the pipe centering ring) unto pipe gasket configuration
at the factory with and location may vary)
or without a sealing
element

Compression ring
(a) (b)
FIGURE 4.24 (a) and (b) Jointing system in ASTM C1208 clay jacking pipe.

used for jointing, as shown in Fig. 4.24a and b. The sealing element is
compressed between bearing surfaces to promote watertight integ-
rity. The ends of the pipe are fitted with a compression ring to distrib-
ute the jacking forces of installation.

Advantages and Limitations
Table 4.9 summarizes some of the advantages and limitations of clay
pipe. The inert nature of clay pipe was the reason behind its wide
acceptance for use in sanitary sewer applications in years past. Resis-
tance to both internal and external corrosion was its main advantage
over other traditional piping materials such as concrete and cast iron.
Clay pipes are also abrasion resistant making it a suitable material in
sewers with high solid content. Its low sensitivity to temperature dif-
ferentials prevents any significant expansion and contraction when

Advantages Limitations
1. Resistant to both internal and 1. Available for gravity applications
external corrosion only because of the
2. Proven history of long life of the characteristics of the pipe
pipe itself 2. Sensitive to bedding conditions –
3. Improved joints have been may be subject to shear and beam
available since 1970 failure
4. Ability to handle high 3. Poor joints in pipe installed prior
compressive forces, making it to 1970 may lead to leakage and
ideal for jacking installations root intrusion problems
5. Abrasion resistant 4. Short lengths, resulting in more
pipe joints
5. Very brittle – frequently high
breakage during shipping and
handling
TABLE 4.9 Clay Pipe’s Advantages and Limitations