Inspection, Qualification and Safety
Inspection, Qualification and Safety
Inspection ensures welds meet code requirements. Inspectors must be qualified (e.g., CWB certified) and familiar with CSA W59 and W47.1. Inspection includes visual examination before, during, and after welding, as well as non-destructive testing (NDT) methods such as ultrasonic, radiographic, magnetic particle, and liquid penetrant. Documentation is critical: inspection reports, WPS/PQR records, and welder qualifications must be maintained. Safety is paramount: welding hazards include electric shock, fumes and gases, arc radiation, fire, and explosions. CSA W117.2 provides safety guidelines for welding. Personal protective equipment (PPE) includes welding helmet, gloves, flame-resistant clothing, and respirators when needed. Ventilation must be adequate, especially for stainless steel welding (hexavalent chromium) and galvanized steel (zinc fume).
A common trap is assuming visual inspection alone is sufficient for critical welds; NDT may be required by code. Another trap is neglecting safety precautions for confined spaces or hot work permits. Also, inspectors must verify that welders are qualified for the specific job and that the WPS is being followed.
Worked example: A welder is welding inside a tank. Before entry, a confined space permit is required, and atmospheric testing must be done. The welder must use a respirator if ventilation is inadequate. The inspector checks that the welder's qualification covers the process and position, and that the WPS is at the site. After welding, the inspector performs visual inspection and may require radiographic testing per code.
Rule of thumb: Always follow the hierarchy of controls: eliminate, substitute, engineer, administrate, and use PPE last. For welding, engineering controls like ventilation and fume extraction are preferred over respirators.