Fiber-Optic Sensing for Seating Stress Quantification in Semi-Metallic Gaskets

Abstract

Modern sealing components are essential in today’s industry. The recent global focus on environment, sustainability and safety is encouraging gasket manufacturers to innovate and think of the gasket of tomorrow. Not only are performance expectations increasing rapidly, but advancements in gasket manufacturing and material technologies are producing gaskets that — in both theory and practice — generate tighter seals and reduce harmful emissions. The major impediment to attaining these results in the field is the lack of advancement in assembly accuracy and real-time monitoring of gasket stress. Currently the user relies on industrial calculation standards that are designed to determine the required bolt load to maintain a leak free seal over the required timeframe. Such calculations often yield a proper approximation of the situation, but they inherently rely on simplifications and assumptions. Furthermore, the correct execution of installation protocols is difficult to verify. The state-of-play does not allow in-situ measurements of the seating stress in the gasket. This study addresses state-of-the-art shortcomings in bolted flange connections and proposes a solution to mitigate them by means of sensors. We successfully integrate optical fiber sensors inside semi-metallic gaskets and experimentally demonstrate the direct measurement of seating stress. Such in-situ seating stress quantification enables installation and condition monitoring serving an optimal lifecycle prediction and failure prevention. As such, this approach contributes to increased sustainability of bolted flange connections.