Quality control in fabrication integrates inspection and testing throughout manufacturing processes, catching defects when correction is least expensive and preventing nonconforming products from reaching customers. Strategic QC placement at critical fabrication stages maximizes effectiveness while controlling costs.

Fabrication QC sequence typically includes receiving inspection verifying incoming material quality and traceability, fit-up inspection before welding ensuring proper joint preparation and alignment, in-process weld inspection catching problems during production, post-weld NDE detecting internal discontinuities, dimensional inspection confirming geometric accuracy, and final inspection before customer acceptance.

QC hold points require inspector verification before proceeding to next operations. For pressure vessels, typical hold points include material verification, fit-up before critical welds, weld examination before covering, hydrostatic testing, and final data package review. Hold points prevent defects from progressing through fabrication.

Inspection documentation creates objective evidence of quality: material test reports, weld procedure and welder qualification records, NDE reports with radiographs or UT data files, dimensional reports, pressure test results, and compilation into final data packages. Documentation enables traceability and demonstrates code compliance.

Modern QC incorporates digital tools including computerized radiography, automated ultrasonic testing with permanent records, 3D laser scanning for dimensional verification, and digital documentation systems. Technology improves inspection reliability, productivity, and record-keeping.