Ultrasonic processes seam welding

Ultrasonic horns can vary in size up to a maximum of about 24 cm by 4 cm if rectangular, or about 9 cm in diameter if circular. The actual shape of the hom relates to the particular welding operation to be achieved. One of the advantages of ultrasonic welding is that the same process can incorporate an ultrasonic cutting edge to enable cut and seam processing. 

After the cause was identified, all welding seams, not only those directly affected, were removed on site under extremely difficult confined conditions and rewelded using improved welding parameters. This process took approximately 4.5 months, and was completed in accordance with a schedule drawn up for the operation. Ultrasonic tests shortly after repair and recharging with sodium and one year later showed no evidence of cracks. An examination of the complete plant for similar evidence showed that the cold trap vessels were also affected. However repair work on these was very much easier as disassembly and reassembly were relatively simple and repairs could be carried out in the workshop. 

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