Lipp GmbH welding process

Leak-proof - weld seam inspections by quality assurance systems from hema

Container construction specialist Lipp GmbH relies on quality assurance system from hema electronic for weld seam inspections.

3,000 m3 or 3 million litres of water - that is the maximum capacity of a stainless steel drinking water tank manufactured by Lipp GmbH, based in Tannhausen. Such figures make it more than clear that the production, installation and commissioning of such a tank is all about safety. The 3-5 mm thick stainless steel strip used remains dimensionally stable, even with tanks several metres high. This is made possible by stiffening ribs that are formed onto the incoming sheet metal strip during the manufacturing process. The optical inspection system seelectorICAM weld from hema electronic used by Lipp reduces reworking in the quality assurance of the weld seams and thus the risks which could occur due to defective seams on the struts.

Elevated tanks for drinking water storage play a role above all in the municipal drinking water supply. The material stainless steel is particularly well suited for such tanks because it is hygienic and resource-efficient. Since the tanks can have a diameter of up to 20 m, Lipp installs them directly at the customer's site. A mounting ring determines the intended size of the tank and gives it a perfectly round shape. From a steel coil, a machine developed by Lipp itself unrolls a strip which is given the unique reinforcing ribs, which are attached at intervals of 75 cm, in the profiling machine. The container is then fully automatically welded on both sides.

The visual inspection of the welding seams is carried out by the seelectorICAM weld system developed by hema. This intelligent camera system provides a clear picture of the working field even under extreme lighting conditions around the arc and thus allows monitoring on a monitor. Parallel to the erection of the tank, the video system inspects the welded seams inside and outside in the same work step and at the same speed and provides the fitters with the result for further processing on the monitors. Without waiting times or intermediate steps, the Lipp experts on site have certainty about the quality of the welded seams on the newly constructed drinking water tank. Important parameters for the welding process such as current strength and voltage, wire feed or gas quantity can be stored in the system by the Lipp employees and thus be used for the weld seam inspection. Manual inspections of the seams are reduced to the points detected in the process and are eliminated immediately.

For Lipp, the automated camera-supported weld seam monitoring has another advantage: "Our employees must be able to adjust the parameters according to the requirements of the tank, detect welding defects and carry out manual reworking. For this alone we would actually need three to four qualified experts per tank. But these do not grow on trees. The automation provided by the hema quality assurance system relieves us of some of the tasks here", says Matthias Kuck, head of the drinking water systems division at Lipp.

The hema quality assurance system seelectorICAM weld works so efficiently that other methods for checking the strength of the weld seams, such as using X-rays, are no longer necessary. "To have a tank of such a size X-rayed is very expensive and time-consuming and by using our system it is unnecessary because we check all relevant spots for workmanship and quality during the assembly", says Oliver Helzle, CEO of hema electronic.

For Lipp GmbH the visual inspection system from hema electronic offers three essential advantages:

  • It guarantees safety, which is indispensable for the construction of an elevated tank for drinking water.
  • It achieves effectiveness by efficiently detecting welding defects and thus minimising safety risks.
  • It saves time and costs by avoiding inspections and by inspecting the welding seams in parallel with the construction of the tank.