Fused PVC Pipe The Answer For Pipebursting Projects Across The Country

November 2010, Vol. 65 No. 11

“Quick and quiet,” is how John Riera, Water Resources manager for St. Petersburg, FL, describes a recent pipe bursting project using fused PVC piping in a residential area of his city. “Homeowners appreciated the speed and minimal disruption of the project,” he says. “We didn’t have a single complaint.”

Speed of installation and reduced surface disruption and damage are among the main reasons communities across North America are shifting to fused PVC piping in pipe bursting projects. Ease of upsizing and the ability to use standard fittings and compatible materials are other key factors.

St. Petersburg used fused PVC in a pipe burst of 1,200 linear feet of eight-inch cast iron pipe located just a few feet below manicured lawns and driveways. Disruption of the surface in this expensive residential area was not an option.

Billings, MT, burst an aging water main and chose to replace it with fused PVC pipe which had both a higher safe pull force and a higher inside diameter (ID) to outside diameter (OD) ratio than alternative piping materials.

And in California, several communities are using fused PVC for pipe bursting, including the city of St. Helena which rehabilitated and upsized a failing water line tucked between a highway, rail line and historic vineyards.

The developer and provider of Fusible PVC piping systems is Underground Solutions Inc. (UGSI) of Poway, CA. The company’s Bo Botteicher explains that the most common difficulty with pipe bursting projects is the increase in pipe diameter, or upsizing, of the replacement pipe compared to the existing pipe.

Fusible PVC pipe has a reduced wall thickness and hence a smaller OD due to the hydrostatic design basis for PVC, in general. These features result in higher flow rates and smaller bore hole requirements, important considerations in pipe bursting applications where enlarging the piping channel could lead to surface disruption, interference with other utility lines, or other issues.

“Eliminating or reducing the degree of upsizing in pipe bursting reduces the risk that soil displacement from the operation will disturb adjacent underground utilities or cause surface heave,” Botteicher says. “In the past, PVC pipe required gasketed or solvent cement mechanical joints, and these joining techniques often limited or prevented its use in trenchless applications.”

Now, however, UGSI technology is enabling customers to install continuous, monolithic, gasket-free PVC pipe - with high-strength fused joints - and take advantage of the hydraulic efficiency, stiffness, ease of repair and lower cost of PVC over alternative piping materials.