Ultrasonic Monitoring of Pipe-Wall Thickness and Thinning Rate

Monitoring of pipe wall thickness and corrosion/erosion rate are important issues in power generation and petrochemical industries. The pipes are usually subject to erosive and/or corrosive environments and any failure can be catastrophic. While periodic manual ultrasonic thickness gauging is the common practice in many industries, in certain cases, where higher accuracies are required, continuous monitoring systems are in demand. This paper introduces a measurement algorithm which can accurately measure the pipe wall thickness and estimate the rate of wall thinning. The algorithm incorporates a model-based estimation technique for estimating the pipe wall thickness and thinning rate. It is an on-line non-intrusive ultrasonic thickness measurement tool for quick and accurate estimation of the erosion/corrosion rate and remaining pipe wall thickness. The technique is applied to experimental data. The results show that the system can measure thinning rates as low as 10 μm/year within 5 days of data collection.