Design of a Novel Wearable Sensor Device for Real-Time Bolted Joints Health Monitoring

Flanged valves are ubiquitous in oil and gas pipeline networks. The valves help to both connect pipes together and control the flow of fluids. Depending on the location, the valve may experience high temperatures, high pressures, and corrosive agents, all of which degrade the integrity of the flange connection. Thus, flanged valves require regular inspection and maintenance. However, in cases where the valve is located in inaccessible areas, regular inspection can be difficult and costly. While certain methods are currently available for automatic inspection of flanged valves, they often suffer from impracticality issues, such as intrusiveness, unintuitive operation, or sensor fragility. Therefore, this paper introduces a sensing device that, as inspired by wearable technology, can be easily and noninvasively "worn" onto the flanged valve and performs measurements in real-time. The device is composed of piezoelectric lead zirconate titanate (PZT) transducers fortified by a layer of cushioning rubber and a metallic outer layer. This paper presents the design of the device, and verifies its performance using a 12-bolted flanged valve recovered from the field. The device is able to accurately track the tightness of the bolted connections. Unlike prior PZT-based monitoring methods, this device shows great promise for practical application.