Effect of high temperature on structural behaviour of metal-to-metal seal in a pressure relief valve

This paper presents a numerical study involving the deformation of contact faces for a metal-to-metal seal in a typical pressure relief valve. The valve geometry is simplified to an axisymmetric problem, which comprises a simple geometry consisting of only three components: A cylindrical nozzle; which is in contact with a disc (representing the valve seat on top); which is preloaded by a compressed linear spring. The nozzle-disk pair is made of the austenitic stainless steel AISI type 316N(L) steel, which is typically used for power plant components. In a previous study, the macro-micro interaction of Fluid Pressure Penetration (FPP) was carried out in an iterative manual procedure at a temperature of 20°C. This procedure is now automated and implemented through an APDL script, which adjusts the spring force according to the current depth of FPP at a macroscale to maintain a consistent seal at elevated temperatures. Based upon the obtained results, specific suggestions to improve the leak tightness of the metal-to-metal seals at elevated temperatures are formulated.