Evaluation of Welding Process Selection and Quality Control Practices in Fabrication Workshops in the Warri Petroleum Industrial Zone

The quality and reliability of welded fabrications in the oil and gas equipment sector of the Niger Delta are of direct commercial and safety significance, as defective welds in pressure vessels, piping, and structural components can result in catastrophic failures with severe consequences. This study evaluates welding process selection criteria and quality control practices in ten fabrication workshops serving the Warri Petroleum Industrial Zone in Delta State. A structured diagnostic framework was applied, combining technical interviews with workshop managers and certified welders, review of welding procedure specifications and welder qualification records, and physical inspection of completed weldments using visual testing and dye penetrant methods. Process selection decisions were assessed against the requirements of AWS D1.1, ASME Section IX, and the applicable project specifications. Findings showed that only four of ten workshops maintained documented welding procedure specifications covering the range of joint configurations and material grades regularly fabricated. Non-destructive testing was conducted internally in only two workshops, with others relying solely on customer-supplied third-party inspection. Dye penetrant examination of randomly selected test welds identified surface-breaking defects in 23 percent of specimens, predominantly incomplete fusion and porosity. The study recommends mandatory adoption of weld quality management systems aligned with ISO 3834, enhanced regulatory oversight by the Standards Organisation of Nigeria, and structured welder re-qualification programmes in the sector. Keywords: welding quality control, fabrication workshop, petroleum industrial zone, non-destructive testing, Warri.