Precise booster bending for boiler construction in the energy industry

Schwarze-Robitec’s booster bending solution is the method of choice for companies looking to precisely bend high-strength materials for tube serpentines used in boiler construction. It enables even the smallest of bending radii to be achieved while ensuring minimal wall thickness reduction and optimal ovality. Schwarze-Robitec’s CNC DB machine line delivers top performance and even exceeds the tolerance specifications set out in international norms – qualities that Est Industries has been valuing for over two decades. The French company, which specialises in industrial boiler construction, recently ordered a CNC 100 DB, its fourth tube cold bending machine from Schwarze-Robitec’s Boiler & Power series.

Est Industries specialises in industrial boiler and tube construction. The company has around 140 members of staff at its two sites in France and is a market leader in Europe. Est Industries began placing its faith in Schwarze-Robitec tube cold bending machines back in 1996. Since then, the machines have really proven their worth in bending high-strength and high-heat-resistant steels.

Technology – application – challenge

Efficient processes in power plant construction largely depend on material design and space requirements for the installed pipelines. The solution involves using high-strength – and thus wear-resistant – materials and efficiently utilising the space available by ensuring bending radii are as small as possible. The challenges this creates for the tube bending process are something that Est Industries overcomes with the aid of Schwarze-Robitec’s high-performance booster bending machine. The CNC 100 DB machine is capable of bending tubes with an external diameter of up to 114.3mm and a maximum wall thickness of 7.1mm. This machine ticks all the boxes for the bending process. In addition to generating enough bending force to bend the high-strength materials, the special booster bending solution also allows the forming process to be steered with precision. Furthermore, it enables companies to meet wall-thinning and ovality requirements within the applicable boiler construction regulations, even with the smallest of bending radii of 1°x°D.

Fulfilling tolerance specifications

Modern heavy-duty boilers are exposed to process temperatures of over 600°C. Pipeline systems therefore need to meet highly stringent safety standards and tolerance specifications. Through a combination of pressure control and tool construction, machines from the Boiler & Power series even exceed the tolerance specifications of the norms EN 12952 and ASME B31.1 along with other international standards. Wall thinning can be limited to a maximum of around 12% for bending radii of 1°x°D. The reduced level of wall thinning gives rise to substantial financial benefits due to the decreased amount of materials used. Ovality remains under 10%, guaranteeing flow properties in boiler construction and eliminating interruptions.

Flip-over table for producing tube serpentines

In order to achieve tube meanders with particularly small bending radii with the CNC 100 DB, Schwarze-Robitec additionally installs a flip-over table in front of the booster bending machine, enabling tube serpentines to be effectively and securely flipped 180°C. Multiple arm pairs can flip tube serpentines with section lengths of up to 9,000mm. The flipping motion is performed in sync with the movement of the bending machine’s index head.

Est Industries has continuously expanded its range of machinery over the past years with the addition of tube cold bending machines from Schwarze-Robitec. With its new CNC 100 DB, the company continues to focus on outstanding bending quality to ensure it is able to optimally meet the growing demands in boiler construction.