Virginia Department of Transportation Duraliner™ for Pressure Line Rehabilitation of a Fire Loop

In April 2006, UGSI was contracted by the Virginia Department of Transportation (VDOT) to supply 200 linear feet of 6" DR14 Duraliner™ for a pressure line rehabilitation of the Hampton Road Bridge/Tunnel (HRBT) fire loop. The existing 200 linear feet section of 8" DI fire loop was leaking due to a gasket failure which may have been damaged or left out entirely during installation more than 60 years ago.

Duraliner™ was selected because of its unique gasket-free design and close fit technology which allows for maximum flow rate. It is also the only fully pressure rated stand-alone structural lining system available.

After the security clearances were granted for UGSI, a crew of three along with support labor from the GC, Warwick Plumbing & Heating out of Newport News, VA, completed the rehabilitation project which was underneath the roadway in the Hampton Tunnel. The project was carried out over three consecutive nights to minimize lane closures and traffic disruptions during the day. The crew worked at night because the tunnel had to be closed for the Duraliner™ expansion procedure and the equipment and material staging in the lower sub duct.

Because of the limited accessibility in the lower sub duct, staging the equipment and materials was challenging. After the staging was accomplished, UGSI completed seven fusion welds in about three hours. Following fusion, the 6" DR14 Duraliner™ starting stock was efficiently installed and expanded to 8" for a close fit to the host pipe. The rehabilitated line was then pressure tested by the GC at 200 psi for two hours. There was a zero drop in pressure for the duration of the test.