What Is a Welding & NDT Inspection?
A Welding & NDT Inspection is a specialized quality control examination performed by certified welding inspectors (CWI, CSWIP, or equivalent) to verify that welds meet the required codes, standards, and specifications. Weld quality is critical in applications where structural failure could result in injury, environmental damage, or significant financial loss — including pressure vessels, structural steelwork, piping systems, bridges, offshore platforms, and heavy machinery.
Welding inspections go beyond visual assessment. They encompass review of welding procedures, welder qualifications, material traceability, and may include non-destructive testing (NDT) methods to detect internal defects that are invisible to the naked eye.
What Does a Welding & NDT Inspection Cover?
- Welding Procedure Specification (WPS) review — Verification that the welding procedures being used are qualified, documented, and appropriate for the materials and application. This includes checking welding process, filler metals, preheat and interpass temperatures, and post-weld heat treatment requirements.
- Welder qualification verification — Confirmation that welders and welding operators hold current, valid qualifications for the processes and positions they are performing. Welder qualification records (PQR/WPQR) are reviewed.
- Visual weld inspection (VT) — Systematic visual examination of completed welds for surface defects including cracks, porosity, undercut, incomplete fusion, excessive reinforcement, spatter, and misalignment. Visual inspection is the most fundamental and widely used inspection method.
- Non-Destructive Testing (NDT) — Depending on the application and code requirements, NDT methods may include Ultrasonic Testing (UT), Radiographic Testing (RT), Magnetic Particle Testing (MT), Dye Penetrant Testing (PT), or Phased Array Ultrasonic Testing (PAUT) to detect internal and sub-surface defects.
- Dimensional verification — Checking weld dimensions (throat, leg size, reinforcement height) against drawings and code requirements using welding gauges.
- Material traceability — Verification that base metals and filler materials have proper Material Test Certificates (MTC/MTR) and can be traced to their source.
- Code compliance — Inspection against applicable codes and standards such as AWS D1.1 (Structural Steel), ASME Section IX (Pressure Vessels), EN ISO 5817 (Quality Levels), API 1104 (Pipelines), or project-specific specifications.
Common Applications
- Structural steel fabrication (buildings, bridges, towers)
- Pressure vessels and boilers (ASME, PED compliance)
- Piping systems (oil & gas, process industries)
- Offshore and marine structures
- Heavy machinery and equipment frames
- Storage tanks and silos
- Automotive and transportation components
Report Delivery
Inspection reports are delivered within 24–48 hours and include visual inspection findings, NDT results (if applicable), dimensional records, non-conformance reports, and compliance status against the specified codes. Reports are issued by qualified inspectors with relevant certifications.
Why Use InspectionService.com?
Submit one request and receive quotes from providers with certified welding inspectors in your manufacturing country. Compare qualifications and pricing — completely free for buyers.
Frequently Asked Questions
Inspection of weld quality plus non-destructive testing (NDT) by certified inspectors — for structural, pressure, and safety-critical fabrications where a weld failure carries real risk.
Common methods are visual (VT), dye penetrant (PT), magnetic particle (MT), ultrasonic (UT), and radiographic (RT) testing — chosen by material, joint type, and the governing code.
Recognised certifications such as CSWIP, AWS CWI, or ASNT/PCN NDT levels, depending on the standard your project requires.
For steel structures, pressure vessels, piping, and any fabrication where weld integrity is safety- or code-critical.
It uses the per-man-day model, though specialist certified work can price above standard consumer-goods inspection. See our cost guide.