The Problem:
Install two tunnel runs 600 feet long and 1,200 feet long to access raw drinking water from Standley Lake to serve a rapidly growing Denver suburb. The steel pipe installed in the tunnels was to be the actual carrier pipe and, as such, had to be capable of handling internal pressure as well as withstanding high external groundwater pressure.

The Solution:
Utilizing the Permalok Type 7 gasketed connectors, the contractor was able to provide a pressure capable steel lined tunnel that required no field welding or field repairs to the 50 mil Powercrete® external coating. Welding each section to meet the requirements of the job would have taken certified welders six to eight hours per section, not including inspections and repairs, and would have added at least 40 days to the completion date.