>> Piping systems play an important role in gas and oil transferring system. In the piping system, there are many elements, such as valves and flow meters. In order to check their normal operating conditions, each signal from each element is displayed on the monitor in the pipe control room. By the way, there are several accidental cases in the piping system even if all signals from the local elements are judged to be normal on the monitor in the control room. Further, opposite cases often happen even the monitor shows abnormal while the local elements work normal. To overcome this abnormal functions, it is not so easy to construct the environment in which sensors detecting the working states of all elements installed in the piping system. In this paper, a new non-contact measurement technique which can calculate the elements' delicate displacements by using a PIV(particle image velocimetry) and diagnose their working states by using a neural network is proposed. The measurement system consists of a host computer, a micro system, a telescope and a high-resolution camera. As a preliminary test, the constructed measurement system was applied to measure delicate vibrations of mobile phones. For practical application, a pneumatic system was measured by the constructed system.

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In this study, among plant equipment, valve and piping fitting which is vulnerable to waterhammer was selected for diagnosis. Impulsive vibration by waterhammer was measured and applied to HIL simulator as operation data using HILS method for reproducing failure mode and life prediction of them. For effective measuring vibration, accelerometer was adapted for in the poor surroundings. Measurement results shows max. peak-to-peak vibration displacement was 21.40 mm caused by waterhammer on the valve etc., which could affect structure stability of plant equipment. After that, using the acquired data, the vibration durability of the expansion joint was tested. Meanwhile, in the case of vibration durability, internal pressure in the expansion joint was proposed as main stress factor of durability life, life prediction model was induced by curve fitting along with the datum at each pressure and verified. Thus, a further study will develop mixed life prediction model which will contain another stress factor such as temperature.