Conventional NDT
The core NDT methods for finding surface and subsurface flaws in welds, castings and plant components, carried out on site and in the workshop.
About conventional NDT
Conventional NDT covers the established techniques that most integrity work relies on. Each method suits a particular type of flaw and material, so the starting point is always the component, the expected damage mechanism and the standard the work is carried out to.
Magnetic particle inspection detects surface-breaking and slightly subsurface flaws in ferromagnetic materials such as welds and castings. Dye penetrant inspection reveals surface-breaking flaws in non-magnetic materials by capillary action. Ultrasonic testing measures wall thickness and detects flaws using sound waves, and visual inspection underpins all of it.
We carry out this work by qualified NDT technicians on site and in workshops, so components can be tested where they are rather than being taken out of service to travel to a laboratory.
Methods and scope
A typical conventional NDT scope is built from the methods below, selected to suit the material and the flaws being looked for.
- Magnetic particle inspection of welds, castings and forgings
- Dye penetrant inspection of non-magnetic components
- Ultrasonic thickness measurement on pipework, plate and vessels
- Ultrasonic flaw detection in welds and parent material
- Visual inspection of welds, surfaces and general condition
- Weld inspection to the applicable acceptance criteria
- Corrosion and erosion monitoring at set measurement points
- On-site testing and workshop testing of removed components
Choosing the right method
Surface flaws in steel
Magnetic particle inspection finds surface-breaking and near-surface flaws in welds and castings quickly and reliably.
Non-magnetic materials
Dye penetrant inspection reveals surface-breaking flaws in stainless steels, aluminium and other non-magnetic components.
Thickness and internal flaws
Ultrasonic testing measures remaining wall thickness and detects internal flaws without cutting into the material.
The essential first look
Visual inspection guides where the other methods are applied and often catches the obvious before it is missed.
Reporting and recommendations
Every conventional NDT job produces a clear report that records the method used, the equipment and settings, the areas examined and the indications found, assessed against the relevant acceptance criteria.
Thickness readings are set out against the measurement locations so they can be compared with previous surveys and used to track corrosion rates over time.
Reports are written by the technician who carried out the work, so the findings and any recommendations reflect first-hand knowledge of the component and how it was tested.
Related inspection services
Need conventional NDT on a component or weld?
Speak with our team about MPI, dye penetrant, ultrasonic testing and visual inspection on site or in the workshop.