ROANOKE TIMES
Copyright (c) 1997, Roanoke Times
DATE: Tuesday, January 21, 1997 TAG: 9701210072
SECTION: CURRENT PAGE: NRV-3 EDITION: NEW RIVER VALLEY
DATELINE: PULASKI
Drivers and passengers in the some 13,000 vehicles that use Bob White Boulevard each day will not have to spend the next several weeks making detours, thanks to a new method of fixing sewer lines.
Cracks were discovered in a line running more than 18 feet below the road by the town's mobile underground camera. One way to repair the pipe before it collapsed would have been to dig it up and divert traffic until it was completed.
But Con Line Co. of Salem offered another way to do the job, and the town used it.
The alternative is a relatively new process called an Ultraliner, a poly-vinyl-chloride alloy that was pulled by chain cable into the 370-foot section of sewer line from Hudson's Chevrolet on one side of the road through to the other side.
A smaller line is first floated through the section involved, and then the cable is pulled through by that. A hole is drilled in the Ultraliner material, hooked to the cable and pulled through.
Once that was done, 235-degree steam is piped into the line to melt the alloy. The interior of the line is then pressurized, which forces the PVC material against the sides of the interior and creates a new lining that hardens in place.
The heat makes the material very flexible, "almost like a noodle," said Larry G. Conner Sr., president of Con Line Co.
The process took a matter of hours, not counting cleaning out the line beforehand, rather than weeks. The washing-out process is necessary because the liner would simply cover any excess material left on the inside of the line.
"If you leave something hard in there, the liner will conform to whatever you leave in there," Conner explained. "The liner is going to take the place of the line you've got. I think it's the thing of the future."
Representatives of Montgomery County, Craig County and New Castle, Radford and Pearisburg were on hand last week to watch the process, and decide if it is something they might need in the future.
The Ultraliner was developed by a company based in Oxford, Ala. Con Line Co. has the franchise for it in this part of Virginia. It has been used in Roanoke County, New Market, Lynchburg, Salem and now Pulaski.
If a line is close to the surface, Pulaski Town Engineer John Hawley said, it is probably just as quick to dig it up and replace or repair it. "But I see this as a definite use in certain locations" where the line is difficult to reach, he said.
Terry Nester, with Pulaski's engineering department, operates the remote-control camera that explores selected sections of the some 60 miles of sewer line within the town each year. Hawley said the section under Bob White Boulevard was checked because of the amount of water apparently being lost through cracks in the pipe.
"If we hadn't found it with the camera, we'd have found it when it eventually collapsed," Nester said.
As the camera continues to find leaks and the town continues to find ways to fix them, money will be saved by cutting down on the amount of water being lost through leaky lines.
LENGTH: Medium: 65 lines ILLUSTRATION: PHOTO: PAUL DELLINGER/Staff. Con Line Co. of Salem uses steamby CNBto soften a sewer pipe liner. color.