Largest HDPE pipe projects in North America.

Two massive projects involving plastic pressure pipe are both claimed to be the largest ever in North America. One is described as the biggest single use of smooth-wall HDPE pressure pipe, both in terms of continuous system length and diameter. Completed in the fourth quarter 2003, the nearly 30-mile pipeline was manufactured by MTD Pipeline LLC, a joint venture of Martin Marietta Magnesia Specialties LLC and Dow Chemical Co., Midland, Mich., to support the transport of brine solution from a Martin Marietta plant in Manistee, Mich., and a Dow facility in Ludington, Mich.

The 20-in.-diam. SDR 11 pipeline (see photo) is made from DGDA-2490 NT, a new resin with 0.959 g/cc density and 0.08 MI. It's the newest addition to the Continuum family of bimodal HDPEs from Dow Polyolefins & Elastomers, Houston. Produced using Unipol II process technology, it boasts longer life expectancy and outstanding strength for pressure pipe and fittings used in water conveyance, gas distribution, mining, and oil, gas, and chemical processing. The pipeline required 6.3 million lb of resin, representing the largest single use of any PE100-rated material. Tel: [phone] * PT Direct: 368PF

Meanwhile, Uponor Aldyl Co. in Shawnee, Okla., the U.S. subsidiary of the Finnish Uponor Group, has won what is said to be the largest order ever for HDPE gas pipe and fittings. Uponor Aldyl will supply them to a consortium of several Northeast and Midwest utilities. The contract runs for three years and is worth about $9 million a year. It calls for 11.5 million ft of PE2406 and PE3408 pipe and over 100,000 fittings annually.