- ENGINEERING INFO
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A new concept in waterline design and installation has emerged due to the presence of highly corrosive soils throughout the United States. Fort Collins Loveland Water District (FCLWD), located in Northern Colorado, has battled extremely corrosive soils for years. Engineering Manager Terry Farrill said, "Our soils are very corrosive. We've had cases of failed ductile iron pipe and fittings with less than 20 years of service."
Faced with the need for a new 24-inch water transmission line that would pass through some of the most corrosive soils in the District, Terry explored the possibility of utilizing PVC given its resistance to corrosion of any kind. Ultimately, the solution was Fusible PVC&trade. It was an excellent choice for crossings, which included Interstate 25, due to a uniform OD (no mechanical joints), ability to downsize casings and lack of upsizing as compared to HDPE pipe for equivalent hydraulic capacity. Additionally, Underground Solutions had developed a new application for Fusible PVC&trade that greatly reduces the number of metallic components required for large diameter transmission lines, such as joint restraints.
As shown in the diagram above, the concept involved using bell & spigot PVC for all pipe runs that were unrestrained and Fusible PVC® (shown in red) for all restrained pipe. Restrained lengths of pipe 52 LF or less were delivered to the site pre-cut to the correct length, labeled with the Station ID and terminated with a bell, if required for the transition back to bell & spigot. This "hybrid" design enabled FCLWD to eliminate 117 bell restraints, which would have required 316 Stainless Steel or a wrap of Petroleum Tape at a minimum. As an added bonus, the additional trench excavation and time required for two laborers to assemble a 24-inch bell restraint harness every 19.5 LF (estimated at 1-2 hours per joint) - was also eliminated.
Redline Pipeline constructed the new transmission line and found the assembly to be much simpler than "stabbing" pipe every 19.5 LF, which requires care to prevent rolled gaskets and over-belling. Nate Conely commented, "Not having to install bell restraints by using longer sections of Fusible PVC® is great option to eliminate time spent in the ditch bolting up. It may be the wave for future projects. Once the coordination of site layout was achieved, the longer sections of pipe were relatively easy to handle and install." After the installation was complete, Terry added, "Overall, it was a huge benefit to remove so many metallic components from our design. The final product will undoubtedly be one of the most sustainable assets in our system."
|Pipeline Details and Project Summary|
|Project:||Harmony Road Transmission Line|
|Location:||Fort Collins, CO|
|Length & Pipe Size:||HDD: 400 LF 24" DR18 Fusible C905® Open Cut: 3,285 LF 24" DR18 Fusible C905®|
|Pressure Test:||150 psi for 2 hours|
|Installation:||Open Cut, HDD and Jack & Bore Carrier|
|Owner:||Ft Collins Loveland Water District, Terry Farrill|
|Engineer:||The Farnsworth Group, Rick Pickard|
|Contractor:||Redline Pipeline, Nate Conley|
|UGSI Contact:||Steve Austin (303) 563-9467 firstname.lastname@example.org|