KraussMaffei Berstorff claims large-pipe record; market shows global promise

Calling the system a "world first," KraussMaffei Berstorff has delivered an extrusion line to produce extra-large smooth-walled high-density polyethylene (HDPE) pipe in diameters up to 2400 mm and with hourly (HDPE) output of 1700 kg. P.E.S. Co., which is a longtime KraussMaffei Berstorff customer, has been producing HDPE pipe on a range of KM's single-screw extruders for almost a decade, including extra-large pipe up to 1600-mm in diameter. Produced in the Persian Gulf, the large pipes are primarily used to supply seawater to desalination plants and cooling water to oil refineries.

In addition to KM's single-screw extruder, the system utilizes a spiral-distributor and runs high melt strength polyethylene (PE) XLS12B from Total Petrochemicals. A KM spokesperson told MPW that to his knowledge, this is the first extrusion line in the world for the production of smooth plastic pipes with a diameter up to 2400 mm, eclipsing the usual limit of 1600 mm and the "extremely seldom" 2000-mm line.

The extra large pipe-extrusion line will allow P.E.S. to add smooth-walled HDPE pipes in diameters of 1800-, 2000-, 2200-, and 2400-mm. The system includes a KME 150-36 B/R single-screw extruder and a KM-RKW 40-2400 pipehead. The spiral-distributor design accounts for a material's rheological properties and utilizes a KraussMaffei Berstorff calibration system. By minimizing wall-thickness variations, the line can result in substantial material savings in the large pipes. That consistency also results in more uniform pipe dimensions, which help ensure tight joints in installation.

KraussMaffei Berstorff believes its 36D single-screw extruder, spiral-distributor tooling, and efficient calibration and cooling systems have helped it gain market share in the large-pipe-extrusion market. The company notes that in pipe production, material costs can account for up to 90% of total manufacturing cost, making stringent adherence to tight tolerances a money saver.

Recent sales successes in the market include a production line featuring a KME 105-36 B/R single-screw extruder and a KM-RKW 37-1200 pipehead that went into operation with Wsam Pipes Co. Ltd. in Sudan in early 2010, with an output of 1100 kg/hr. The pipes produced, which range in diameter from 500 to 1200 mm, will transport water. In Vietnam, the company delivered a line to Binh Minh Plastics for the production of HDPE pipe between 710 and 1200 mm in diameter. Korea's Kunsul Plastic Pipe Co. Ltd. took delivery of a KME 90-36 B/R single-screw extruder and a KM-RKW 36-800 pipehead for HDPE pipe manufacture. In Turkey, Pakpen will use a KraussMaffei Berstorff line and downstream units to produce pipe in diameters from 800 to 1600 mm with output of 1700 kg/hr. Other recent sales have come in Australia where it sold a large-pipe extrusion line that includes a coextruder to produce the functional outer layer. In Russia, a number of projects for large pipe production are on track for conclusion, as is a project in South America.

Big, bigger, biggest
A number of extrusion equipment suppliers serve the large-pipe market and vie for the title of world's largest line. Reifenhäuser announced in 2004 that in cooperation with Norwegian pipe manufacturer Pipelife, it was building an extrusion unit capable of producing HDPE pipes up to 2000-mm in diameter. The line was to be provided with a single-screw extruder with screw diameter of 150-mm and 33D (L/D) ratio especially designed by Reifenhäuser for high performance.

Battenfeld Extrusionstechnik (former BEX now battenfeld-cincinnati) supplies complete lines for the production of large polyvinyl chloride (PVC) or polyolefin pipes in diameters up to 2000 mm. In 2007, BEX subsidiary American Maplan publicized the installation of a high-output 48-inch-diameter (1200-mm) system for PVC pipe, with vinyl holding more market share in North America than polyolefins. At the heart of the unit was an AMC/BEX 168-mm high-torque twin-screw extruder, with an RD 24-48 dual spider die head capable of 5300 lb/hr of output.

At NPE2009, American Maplan displayed its PO 125 VSI die for polyolefin pipe, which is available for diameters of 10-2000 mm and can be configured for co-extrusion as well as monolayer applications. Also at its booth, the company displayed a portion of a HDPE pipe 63-inch (1600-mm) in diameter-the largest diameter HDPE pipe ever produced in the U.S. according to the company.

In 2008, Cincinnati Extrusion (now integrated into battenfeld-cincinnati) launched its Kryosys lines for the production of smooth mono- and multi-layer PE or PP pipes, with diameters ranging from 110 to 2000 mm.

Market promise in aging pipes
Tony Radoszewski, executive director of the Plastics Pipe Institute (PPI; Irving, TX), notes that PE has been used in gas-collection systems in 1957, with over 3 billion feet of the pipe in the ground for gas distribution. The next big market in the U.S., according to Radoszewski, could be in water, with a two-year-old Environmental Protection Agency (EPA) study estimating that it would take 20 years and $540 billion to replace failing pipes that constantly leak water. In larger cities, many of the metal pipe systems were put in 100 years ago with many starting to fail at the same time, as some 250,000 give way every day.

In addition to the water-conservation argument, the PPI argues that plastic pipe has a lower carbon footprint in its production, transport, and installasion. PE, for instance, melts at 275°F, while iron is processed at 2795°F. In terms of weight, a 300-ft 36-inch diameter pipe would weigh 7200 lb in plastic. The same pipe in concrete would weigh 247,500 lb. In North America, PVC dominates water and sewer lines, with around 66% of the market, while PE claims 3%, with 30% in ductile iron and 1% in concrete. In storm sewer piping, concrete is the dominant player. —Tony Deligio