Non-Intrusive Inspection (NII) refers to inspecting assets, such as pressure vessels, tanks, or other equipment with minimal or no interruption to their operation, i.e. without having to take the equipment offline, or without having to provide internal entry to inspect internal surfaces.
It is practical to increase the interval of the internal inspection by performing intermittent non-invasive inspections. The economic savings associated with non-invasive inspection generally come from not having to isolate, open, and prepare the vessel for entry, and in minimizing the cost of lost production. The cost of the non-invasive inspection itself may be more expensive than the cost of the internal (e.g. visual) inspection since non-invasive inspection is likely to require more sophisticated inspection methods.
Although non-invasive inspections can offer major economic benefits, they must only be employed when they can provide sufficient information about the integrity of the component, particularly when leakage or failure could have safety or environmental consequences. Although RBLX gives both options of Intrusive Inspection and NII, as this exercise could be very critical, a separate module has been developed for NII in RBLX based on DNVGL-RP-G103.
- Shepherd, B.W.O., Gast, M.H., and Bouma, T., 2002. Development of a recommended practice for non-invasive inspections. Journal of Nondestructive Testing, 7(10), p.5.