Joints between diaphragm wall panels are weak spots in wall construction. In this study, a novel leak detection and monitoring system is presented that is based on fiber Bragg grating (FBG) sensing. of the leak detection in pipes using the Fiber Bragg Grating pressure transducer. Two different sizes of artificial leak were introduced on the pipe in ord r to measure the applicability of the FBG sensor in detecting the leak in a pipe. A field study. A fiber Bragg grating pressure sensing system integrating a diaphragm and an L-shaped cantilever beam as a sensitive structure is designed for pressure change monitoring of an oil and gas pipeline in this paper. Leak detection and localisation tests were carried out on a plant scale test rig using mains water for a range of leak sizes.