Submerged arc welding (SAW) is a specialised welding technique that reduces impurities from entering the weld pool by covering the entire arc with a pool of flux, resulting in cleaner welds.

The process is well established in the industry but Steinmüller Africa says its exclusive equipment has enabled it to extend the process to more applications such as fabricating membrane walls for boilers.

The company notes that it is well equipped to offer comprehensive fabrication solutions using its advanced machinery, including one of only two PEMA machines in the country and the only Oerlikon SAW stub welding machine in South Africa. SAW is said to ensure minimal weld repairs and offers a faster weld solution, increasing plant uptime. Steinmüller Africa asserts that its capabilities position it to effectively deliver welding services to meet the growing demands of the energy and industrial sectors.

SAW’s significantly higher welding speed and semi-automatic nature reduce the need for human intervention. It is commonly used to weld plates and pipes, as well as large stub and small stub-to-header assemblies. Steinmüller Africa says its expertise is supported by its fleet of three boom welders, the Oerlikon welding machine for header-to-stub welds and the PEMA machine which features six welding heads for welding membrane walls, offering more welding capacity.

The company explains that the SAW method has few limitations, barring those of in-position welding. Components can be manipulated into the flat position, however, which overcomes this problem, making the thickness of the material the only limitation. SAW also offers a more controlled and efficient process compared to manual gas tungsten arc welding and shielded metal arc welding, which rely on gas and flux-coating respectively for arc protection.

Although SAW offers numerous advantages, it also has some challenges including moisture absorption in the flux and position of welding. Steinmüller Africa says it overcomes these challenges by adhering to rigorous standards, such as ensuring that the flux is baked according to the manufacturer’s guidelines and kept hot during welding to prevent moisture absorption. Welding parameters are carefully determined during planning and are strictly monitored throughout the process. In some cases, production test pieces are welded to ensure the quality meets specification standards. The company highlights the technical skill levels of its welder operators, noting that it provides in-house welder training to ensure compliance with governing standards and to facilitate the optimal use of machinery.