The process includes:

1) Your location is surveyed to determine where Mainlining will access the system. Our trenchless program is typically managed in 600-foot sections with minimal disruption to system users. After surveying, a temporary bypass is installed to secure consumer supply and fire protection.

Click on the top
graphic to see the
Perkins Process on
smaller pipe
and the bottom graphic
for larger pipe.

2) Prior to lining, a pipe cleaner assembly consisting of steel scrapers and a flushing system is passed through the pipeline until all of the tubercular deposits have been removed from the pipe walls. The cleaner is either mechanically winched through the pipe or is propelled by water flow. Water passes through the cleaner to flush solid debris ahead of the unit. Circular squeegees are pulled by a winch-drawn cable to remove standing water and remaining loose solids.

3) For pipes 30 inches or smaller in diameter, remote-controlled lining machines are used, pumping cement mortar to a high-speed centrifugal applicator. This uniformly projects the mortar to the interior wall of the clean, dry pipe. Subsequently, a patented cone-shaped trowel is dragged behind the lining machine to produce a smooth surface. The specified thickness is obtained by coordinating the rate at which mortar is pumped to the lining machine and at the speed at which the unit is pulled through the pipe.

For larger pipes, a manned lining machine is operated by specially-trained personnel. The cement mortar travels to the lining machine on a shuttle buggy, with mechanically driven rotating arms completing the finishing process.