Welder qualification tasks and welding procedure qualification tasks for fixed shell-and-tube heat exchangers
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For fixed tube-and-shell heat exchangers, the tube sheet is made of nickel-carbon steel composite material (6+44 N6+Q345R); the heat exchange tubes are made of nickel (N6), the shell side is made of carbon steel (Q345R 10mm), and the tube box is made of nickel (8mm). What are the welding tasks required, and what tests need to be carried out for welding procedure qualification?
Welding worker tasks generally include: 1. Welding of tube sheets and heat exchange tubes. 2. Welding of tube boxes and casings. 3. Welding of the tube sheet and shell connection. 4. Weld repair and surface treatment. Welding procedure qualification items usually include: 1. Selection of welding materials. 2. Welding parameters (current, voltage, welding speed, etc.). 3. Shape and size of the weld. 4. Welding sequence and direction. 5. Heat treatment method (if required). 6. Welding defect standards and inspection methods. 7. Qualification assessment of welders. .
Relevant repairs and modifications require confirmation and support from those with the appropriate manufacturing qualifications (such as the original manufacturer) as well as the original design team. Individuals cannot repair or modify pressure vessels.