Abstract
Glass reinforced plastic (GRP) pipes with Reka couplings utilize gaskets to create reliable seals under specific angular deflections defined by manufacturers according to relevant codes and standards. Proper sealing is crucial, especially for high internal pressures and large pipe diameters, where double-gasket connections are employed to enhance safety. This study leverages numerical modeling to investigate the performance of double-gasket couplings on angular deflections, focusing on the contact between the gaskets and the pipes. The results are compared to practical tests at lower pressures and indicate that internal pipe pressure is the primary factor influencing maximum angular deviation. Additionally, adding a second gasket does not affect angular deflection or the sealing mechanism, as internal pressure governs permissible angular deviations in GRP pipes. Under increasing deflection, the GRP pipe at the Reka coupling undergoes oval deformations, causing the secondary gasket to detach from the pipe surface faster than the primary gasket and transition into a sliding and separating state. Understanding the behavior of the gaskets and sealing in Reka connections during angular deflections—such as those caused by differential soil settlement or thrust block movement—enhances the design and implementation of these piping systems.