Shape Memory Alloy Sealing Gaskets for High-Pressure Flange Connections

Abstract High-pressure flanges are essential components for joining pipes, ensuring sealing, and preventing liquid and gas leakage. Gaskets play a critical role when subjected to high stresses, situation where they can cause irreversible deformations that, combined with fluctuations in mechanical and thermal loads, can compromise their integrity. The present work aims to evaluate the use of shape memory alloy (SMA) sealing gaskets, specifically NiTi alloys. This work establishes a comparative performance analysis of NiTi and AISI 316 stainless steel gaskets under the same operating conditions. Finite element method is employed to evaluate the mechanical response of both materials under critical loading conditions, including service overpressure, progressive bolt preload loss, and individual bolt loss scenarios. The analysis combines SMA constitutive nonlinearities and contact interactions to properly capture the sealing behavior. Experimental data are used to calibrate the constitutive model for the NiTi alloy. The analysis framework is based on average and local sealing pressures, allowing a detailed comparison between the two materials in terms of their sealing efficiency and mechanical robustness. Results indicate that SMA gaskets present a better performance, improving the contact area of the sealing surface between the flange and the gasket.