Abstract
In recent years, leakage reduction and assessment have become necessary from an environmental protection perspective. It is important to properly calculate the gasket contact pressure to estimate and reduce leakage in the design stage.
ASME PCC-1 and API 660 demand higher gasket stress to prevent leakage in service. Increasing the bolt tightening load is expected to improve the gasket sealing performance while flange face rotation increase. Flange face rotation causes the unbalance in gasket contact pressure distribution: while the maximum contact pressure increases, the area of high contact pressure decreases. It is difficult to evaluate the unbalance in gasket contact pressure distribution experimentally. Therefore, a detailed analysis is essential to assess how this affects the sealing performance. SWG is widely used in oil and gas industry. However, the detailed analysis has been difficult due to the spiral structure and the composite property of constituent materials.
In this paper, firstly, the method for detailed analysis of SWG was proposed. The analysis model was developed by combining a hyper-foam material model of CEG filler with a detailed SWG geometry model. Secondly, the analysis model was validated by uniform compression test by parallel plate. The gasket stress curve simulated by the developed model was well matched in the result of uniform compression test. Finally, the effect of flange face rotation to the compression behavior was studied by the developed model. Based on the contact pressure distribution and the filler compression distribution, the relationship between the overall compression behavior and the interaction of constituent materials was discussed.
