The City of Pasco, WA, recently rehabilitated a leaking 12-inch water pipe that runs under an active railway intersection in the southeast side of the city using a fully structural cured in place lining system.
Two sections of the lead joint, ductile iron pipe installed in 1945 had been leaking for years. Around five years ago, the City of Pasco chose to temporarily reroute the water supply because open cut replacement was out of question. The section of pipe runs 8 feet under six sets of Burlington-Northern railroad tracks. Due to the continual traffic and the importance of the switching yard as a major intersection of railways on the West Coast, shutting down the tracks to repair the leaking pipe was not possible.
Michels Pipe Services was selected to rehabilitate the pipe using the Nordipipe™ lining system offered by SEKISUI NordiTube. A glass-fiber reinforcement gives the liner static, self-supporting properties and allows it to withstand higher internal and external pressures than traditional liners.
The liner is designed as an AWWA Class IV fully structural, stand alone pipe liner and is NSF 61 approved for potable water systems. It can resist internal pressure up to 200 psi, and is manufactured in lengths of up to 1,000 feet in diameters from 6-48 inches.
Michels was able to reline the leaking pipe during a two day session in October 2011. The liner was prepared in at the company's Salem, WA, facility and transported to the site overnight, reducing the time between activating the epoxy resin and the actual pipe installation. This differed from most epoxy methods that require on-site resin preparation. Costs were reduced by preparing the liner in Salem as opposed to assembling an on-site wet-out area.
Michels tackled the project in two separate 275 foot sections. Using a pressure vessel to invert the tube and curing it with steam, each installation took 12 hours. End seals were used to join the liner to the existing ductile iron pipe and after a 150 psi pressure test, the pipe was returned to service.
"The project went as planned in spite of some changing conditions. Michels, the City of Pasco and SEKISUI NordiTube made adjustments on the project to compensate and complete the job," said Chris Tavernier, Michel's onsite supervisor.
SEKISUI NordiTube, headquartered in San Clemente, Calif., offers a variety of trenchless rehabilitation solutions for underground infrastructure, including potable water mains, force mains, gas and industrial pipelines. It is a subsidiary of the global SPR (SEKISUI Pipe Rehabilitation) Group. For more information, visit www.sekisuispr.com.
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