Advantages and characteristics of laser welding pressurised containers and water tanks

  • Butt seam welding replaces overlap seams and prevents unwelded sheet metal edges
  • 3-5 times higher welding speed
  • Simplified welding connection for the base/lid
  • Significantly lower heat input during the welding process minimises thermal distortion
  • Favourable stress distribution of the weld
  • Significantly less spatter compared to conventional methods
  • Optically attractive weld
  • An online quality and process check is possible
  • Optimised conditions for the coating of tank interior and outer skin

Circumferential welding machineCircumferential welding machine

For the production of containers, the laser welding process has particular advantages over the conventional MAG welding system:
For a start, butt welding saves the overlapping material that has to be used for MAG welding. In addition, butt welding of the container body makes further welding of the base/lid easier. The challenge of welding in the area where there is double wall thickness is completely eliminated.

The low heat distortion has a positive effect on the deformability and further processing of the parts to be welded. This is where the laser comes into its own (in addition to the much higher welding speed). Due to the significantly lower heat-affected zone (HAZ) and the much narrower weld seam, significantly less heat penetrates into the component. Less heat input means less heat distortion and consequently, this means a lower and more favourable stress distribution of the weld seam. Another factor in favour of laser welding is less spattering when welding. This results in a better quality and a visually appealing weld seam.

Due to the smaller focal point of the laser compared to MIG/MAG, the seam is also significantly narrower. Of course, all current online quality checks and process checks can be integrated.The best comes last however:  The material used to coat the inside of the container can be significantly reduced because there are no sheet edges, as in the case of overlap welding. This results in further savings that only laser butt welding offers.
    
A complete package from a single source weil technology offers complete packages for the production of containers and uses semi- and fully automatic production in a continuous process chain, from the coil to the complete laser-welded product. These lines can be operated with production capacities of up to 1000 to 1600 parts per shift. Currently we can offer a container production with a pipe diameter of 120 to 600 mm, pipe lengths of 2000 mm (max.) and a sheet thickness of 2.5 mm.The main components of each container manufacturing line are:

  • Coil and straightening station
  • Cutting to the length of circuit boards
  • Transfer units
  • Round bending machines
  • Longitudinal welding machine (casing)
  • Welding of attachments
  • Circumferential welding machine
  • Leak testing station

Depending on the degree of automation and the end product, other machines, such. welding machines for attachments (threaded bushings), brackets and handling/conveyor units are added.

Our specialty: Laser welding
In contrast to conventional production lines, laser technology is mostly used in weil technology's lines. In addition to a high-power laser, CO2 and solid-state lasers or other welding sources can be used, depending on the application (TIG, MIG/MAG, plasma welding).

Higher product quality and flexibility
weil technology's new production lines offer a high level of product quality and are characterised by a high level of productivity and flexibility.

High demands on weld quality in threaded bushes
Threaded bushes act as connecting elements for media-carrying pipelines or sensors. Flexural fatigue stresses occur, especially in piping. Here, the weld seam is exposed to high dynamic loads. In addition, the seam must be gas tight. In addition to the operating pressure, the containers are exposed to a much higher inspection pressure, which places additional demands on the seam.

Published inEquipment