Underground Solutions and King County Install 30" Fusible PVC™ Beneath South 212th Way via Sliplining

In April 2007, Underground Solutions, Inc. (UGSI) was contracted by King County Department of Transportation (KCDOT) Road Services Division - Maintenance Section to provide UGSI's FPVC™ pipe and fusion services for a new drainage line that was installed in a 48" corrugated metal pipe (CMP) beneath South 212th Way. King County provided construction services, including the pipe pull, and the project was completed in May, 2007.

UGSI's FPVC™ pipe was selected for its ability to provide King County with a monolithic and flexible pipe system for a difficult drainage area beneath a busy roadway. Other pipe materials were considered, but due to the depth (up to 50 ft.), shifting nature of the ground above, and the available cross-sectional area (one section was constricted to 34" height), UGSI's FPVC™ proved to be the best alternative. Neither bell and spigot PVC or HDPE pipe could provide the desired ID and buckling pressure due to their greater OD (>36").

UGSIis FPVC™ pipe, with an OD of 32", was sliplined in a corrugated metal pipe at the end of its useful life. FPVC™ pipe allows for maximum flow and maximum buckling pressure (68 psi) in a gasketless, lightweight option. The site constraints, a steep grade in an environmentally sensitive area, required the pipe to be installed using the smallest possible footprint. To accommodate these concerns, UGSI provided pipe segments in 19 ft. lengths, instead of the normal 40 ft. lengths, to allow for greater ease of handling. King County, a traditional user of HDPE pipe, welcomed FPVC™ as a price competitive alternative with a smaller OD, higher buckling pressure, and a weight savings of nearly 50%.

For additional information or reference contacts - contact Patrick Laidlaw.

Set-up of Fusion Machine

Constricted/Damaged CMP

Successful Pull Through

Finished Outfall Area