Validation of leakage control with oil temperature-viscosity relationship for a standard flange gasket model

Abstract

Flange-type gaskets are typical static sealing elements used to connect pipelines, they are widely applied in industry. Gasket sheets are placed between flange surfaces to enhance the sealing performance. Generally, the leakage due to gasket clearance is suppressed or reduced by clamping the sealing surfaces, thus blocking the flow. However, controlling and reducing the leakage can prove difficult. The flange roughness and waviness from partial paths may be existed and the vibration lead to loosening of the clamping bolts. The gasket leakage is increased with the gap and inversely proportional to the viscosity. The lubricant’s viscosity, especially oil, is highly dependent on temperature, with lower temperatures corresponding to higher viscosities, meaning the leakage can be controlled and reduced by lowering the temperature. Therefore, it is feasible to realize leakage reduction by controlling the sealing flanges temperature in view of improving the gasket performance. In this paper, a standard flange gasket with a tiny gap was modeled using the inverse relationship between the oil viscosity and the temperature. The effects of flange temperature, bolt preload torque, gasketed sheet material, gap parallelism, and the vibration frequency and amplitude were examined experimentally and confirmed via theoretical simulations using the thermo-hydrodynamic lubrication theory under the both static and harmonic vibration conditions. Overall, the cooling effect was effective and valid for a standard flange gasket. The leakage from the gap was potentially reduced or suppressed by cooling the sealing flanges for all the included parameters under both static and vibration conditions.