Visual Weld Inspection
Visual Inspection non destructive testing is one of the many ways we test the quality of welds at SureCheck.
During a visual welding inspection a weld is examined visually through the eyes to determine the quality of the weld and identify any discontinuities on the surface of the weld. Some common discontinuities that can be picked up on during a visual inspection include surface cracking, undersized welds, overlap, undercut, either incomplete or excessive root penetration, excessive reinforcement and burn through.
Visual Welding Inspection is sometimes not associated with NDT, but it is the most widely used method of non destructive weld testing within the fabrication & welding industry. Visual Welding Inspection activities will only find surface breaking indications and welding profile imperfections.
All fabrication standards require visual inspection to be performed and various application standards would have varying levels of allowable imperfections to reach a visual inspection of welds standard.
Three Stages of Visual Welding Inspection
Visual welding inspection requirements in standards such as EN 1090 / ISO 3834 / ISO 17637 etc require inspection at three stages. Before, during and after welding.
Pre-weld inspection often involves checking the preparation of the welding joint by an engineer before the weld is carried out and helping to verify some of the variables that might be difficult to check either during or after the weld has been completed. Such things such as misaligned joints, improper cleanliness, and over or undersized root openings can have a massive impact on the quality of the weld. By carrying out pre-weld inspections, we can introduce controls that can ensure your weld is of higher quality.
Inspection During Welding
Visual non destructive testing during welding is largely concerned with following the requirements of the weld procedure specification. This includes such procedures as interpass temperature control, interpass cleaning methods, welding travel speed, shielding gas type and gas flow rate. It is also important to monitor other environmental factors that may have an impact on weld quality, such as wind, rain, and outside temperatures.
Post Weld Inspection
Post weld inspection is a type of certified weld inspection carried out by an engineer to ensure the quality and integrity of the completed weld. While this often involves many different non destructive weld testing approaches, it is important to carry out a visual welding inspection to find surface discontinuities that may have an effect on the results of other non destructive weld testing processes or disguise other issues within the body of the weld.
Standards & Criteria
The visual inspection criteria would have a specific pass or fail criteria to ensure the weld reaches a visual inspection of welds standard, thus visual welding inspection is as important as any other specified method. In some cases, the visual welding inspection will identify such issues that would affect, for example, the fatigue life of a product in service.
Sure Check can assist with all stages of the inspection activity, especially when some clients and / or specifications may require an independent organization with a suitably certified engineer to perform a final visual certified weld inspection to ensure compliance with the specified requirements.