Page 139 - Trenchless Technology Piping Installation and Inspection

Coatings and Linings for Potable W ater Pipe Distributions 105

FIGURE 3.5 Pit Protection.

3.13 Reconnecting Appurtenances
Dependent on liner material and installation method, fittings, valves,
and fire hydrants may need to be taken out, drained; cleaned from all
dirt, dust, and debris; capped; and stored as part of liner installation
preparation. After lining installation, it is necessary to support heavy
valves (12 in. or 300 mm and larger), with treated timbers, crushed stone,
concrete pads, or a thoroughly tamped trench bottom. Fire hydrant must
be installed in a manner which will provide complete accessibility and
minimum possibility of damage from vehicles or injury to pedestrians.
The outside of the hydrant must be above the finished ground.
All valves must be inspected upon reconnection to ensure proper
working order after liner installation. Valves must be set and joined
to a pipe as set forth in the AWWA standards∗ for the type of connec-
tion ends furnished. All valves and appurtenances must be installed
at the correct alignment and rigidly supported. Any damage to these
appurtenances must be repaired or replacement with new ones may
be required.
Local water utilities may provide their own specifications which
must be followed. Some water utilities may prefer to conduct service
lateral and appurtenance reconnections with their own crews, so
contractor’ work ends with the liner installation.

3.14 Surface Restoration and Site Clearing
Backfilling pits are one of the most important phases of water pipe
renewal. The purpose of backfill is not only to fill the pits, but also
to protect the pipes and provide support for valves and hydrants.

∗C222-08, Standard for Polyurethane Coatings for the Interior and Exterior of
Steel Water Pipe and Fittings; C620-07, Standard for Spray-Applied In-Place Epoxy
Lining of Water Pipelines, 3 in. (76 mm) and Larger; C602-06, Standard for Cement-
Mortar Lining of Water Pipelines in Place 4 in. (100 mm) and Larger.