Measurement of the piping elbow integrity using the fiber-optics technique

This paper deals with the development of a non-destructive conditioning monitoring technique for low alloy steel piping elbows. The objective is to develop a technique, which enables on-line monitoring of the flow induced wall thinning of the elbows. The technique involves use of optic interferometry sensors for the measurement of a flow-induced vibration. The special feature of this system is that it provides a non-destuctive method and enables measurement of the very small displacements caused by wall-thinning. The system configuration and the proposed methodology to be employed related to this developmental work has been discussed. The data and information collected on the vibration characteristics of the piping elbows using fiber optic accelerometers has been analyzed. The application feasibility of the proposed fiber optic interferometer in condition monitoring for nuclear power plant has also evaluated. The results obtained so far are very encouraging with respect to the measurement of wall-thinning in the piping elbows.