From corrosion-resistant to thermally conductive, from wear-resistant to pliable: Tube materials used in industry have to meet very different requirements. Tubes made from a single material are often unable to do so. In order to meet these various requirements, the Meeraners process special composite pipes to produce wear and corrosion resistant boiler walls.
Over the past several months, the company, together with its assembly partner, has focused on the qualification and certification of extensive procedure tests for the repair and manufacture of black liquor boilers. Various WPQ tests were carried out in order to handle the welding-related process safely for the composite material used in these boilers.
The base tube consists of a standard boiler tube (1.0325), the outer part of an austenitic alloy (1.4306) or a nickel-based alloy (2.4852). As part of the qualification, both TIG circular welds and UP fillet welds were tested for the manufacturing of boiler walls.
In the circular welds, five WPQ tests were welded-off to cover all possible welding connections in the boiler. The mechanical-technological analyses revealed no abnormalities. The test welds of the boiler walls were also successfully completed. By macroscopic analyses, the required weld penetration could be detected without melting the base pipe.
Based on the positive results, the Meeraners will perform further WPQ tests for welded attachments/parts. Preferably, the MAG method should be used for workshop welding seams.
With this expansion of the product portfolio, Meeraners continues more than 150 years of tradition as a competent plant engineering company and offer its customers innovative solutions.