Efficient production of high-quality district heating pipes at Isoplus – Instead of sawing pipes to length and beveling the pipe ends in a further work step, Isoplus has now turned to a 3D pipe plasma cutting system from MÜLLER OPLADEN to do the job quickly, cleanly and quietly in a single pass. This new system comes replete with technical features.
District heating has gained immensely in importance in recent years, in the Western world and elsewhere. Centralized heat generation and the exploitation of waste process heat from industry have made it an integral element of efficient and sustainable energy use – especially in view of the sharp rise in energy prices and dependence on fossil fuels. District heating makes use of excess waste heat to heat buildings and generate hot water. This also significantly reduces CO2 levels in inner cities and residential areas.
“Long gone are the times when, as in East Germany, pipelines were laid above ground. Modern district heating pipelines run underground, so they have to meet the strictest tightness requirements,” says Axel Kirstein, Managing Director at Isoplus in Sondershausen, Thuringia. The special pipe manufacturer settled here after German reunification because of the plentiful availability of skilled staff and industrial sites. “More than 400 skilled workers are employed here at the plant alone, and our corporate group now employs 1,500 people worldwide.” And in terms of transportation, Thuringia is conveniently located in the heart of Europe.
Pipes up to 1,000 mm and project-specific fittings
At the Sondershausen plant, Isoplus fabricates its pipes from steel with diameters from 20 to 1,000 mm – plus project-specific branches, bends and distribution groups. A high-quality, Freon-free PU foam is used as insulation, which is protected against environmental influences by a fracture-resistant and waterproof PEHD jacket. The pipes and fittings are assembled and welded together as a modular system on site. Leakage detection and localization wires are installed in the insulation layer to identify leaks and moisture along the pipe route so that they can be remedied in a targeted manner.
In production more than 80,000 pipe cuts are currently performed per year. “Previously, we sawed the pipes to length and then beveled the pipe ends on a lathe,” Kirstein explains. This was logistically elaborate, time-consuming and noisy. “For some pipe diameters, the saw took minutes for a single pass. Transport and clamping on the lathe also claimed valuable time and effort.”
High-productivity alternative to sawing
In their search for a forward-looking solution, a maker of special-purpose machines suggested they look into MÜLLER OPLADEN’s technology. “Even the first meetings with the experts made us sit up and appreciate the savings potential as well as the increase in quality,” Kirstein recalls. And so they jointly designed a pipe cutting system inclusive of logistics, which also has a number of special technical features.
Via a 16 m long roller conveyor, the pipes with a piece weight of up to 8,000 kg are fed to the cutting line from their storage location outside the hall. The system’s fully automated cutting table has 12 height-adjustable pipe supports which automatically adapt to the in some cases out-of-round pipe surface and thus provide optimum support over the entire pipe length.
Reliable compensation of surface irregularities
“We can process both thin and thick pipes on it with high precision. During the cutting process, the system also reliably compensates for pipe ovality and even the spiral seams of large pipes,” Kirstein explains. For this purpose, MÜLLER OPLADEN has integrated a special scanning system at the torch of the 6-axis machine. The software uses an algorithm to calculate and smooth the height differences so that the torch can neatly compensate for the height offsets on the pipe surface. As a result, Isoplus obtains flawless, beveled cuts.
The finished cut is impressive with the high degree of planarity of the pipe ends so important for subsequent gap-free assembly on the installation site. After each pipe cut, the system releases the pipe so that pipe pieces large and small can be deposited easily with the aid of ejector arms onto a parallel table and transported for further processing.
Perfectly integrated into production
The new system from MÜLLER OPLADEN is integrated into the Isoplus production process both logistically and data-wise. “The system runs the latest CAM software and is integrated into our ERP system via an interface,” says Kirstein. To permit the required tracking of each pipe, the line has a needle printer that applies the batch number to the pipe surface.
“This system is a high-productivity alternative to sawing,” Managing Director Kirstein continues. “In the end, we get a clean, precision-machined pipe for optimal further processing.”
“We mastered this challenging project by combining our standard machine portfolio and our engineering capabilities to deliver optional and customized solutions,” says an enthusiastic Ralf Hamacher, MÜLLER OPLADEN’s Managing Director.