Page 92 - Trenchless Technology Piping Installation and Inspection

Existing Pipeline Renewal and Replacement Methods 59

Joint
Prefab panels
Injection
Existing
pipe
Prefab panels are inserted into an active sewer and grouted

FIGURE 2.7 Panel lining method. (Source: Channel Line.)

Profile spool
Power unit

Winding
Liner
Existing pipe

FIGURE 2.8 Schematic diagram for spiral wound process. (Source: Sekisui
SPR.)

For non-worker-entry pipes (usually for existing pipe less than 48 in.
diameter), coatings and linings methods can provide improved
hydraulic characteristics and corrosion protection. Additionally, spe-
cific polymer materials may enhance the structural integrity of the
pipeline and seal joints or leaks. The lining materials may include
cementitious materials, epoxy, polyester, silicone, vinyl ester, poly-
urea and polyurethane. They are sprayed directly onto pipe walls using
remote-controlled traveling sprayers. For worker-entry pipes, sprayed
cement-mortars (shotcrete or gunite) are effective and widely used
for renewing pressure pipes and gravity sewers and can be used for
structural purposes. Figure 2.9 illustrates a coating process. Chapter 3
presents a detailed analysis of coatings and linings methods for pota-
ble water pipe applications.