Laser shearography for inspection of pipelines

Shearography is a highly sensitive integral measuring technique to record deformation and strain concentrations on the surface of components. This paper deals with the application of shearography to nondestructive inspection of piping. The principle is based on measuring the surface deformation of the pipe to be inspected by variation of the pressure inside the piping. While shearographic piping inspection is already used for inspection of cooling water pipelines in nuclear and conventional power plants, research work for other types of piping is still going on. The technique is applicable to all kinds of material. Examples for inspection of welding seams in austenitic piping, as well as for connections of piping from reinforced plastics, are given.