With the recent increase of safety and environmental concern, the estimation of leak rate of a gasketed flanged connection in piping systems is an important subject to be studied. In order to estimate the leak rate, the sealing behavior of a gasket must be known. Currently, evaluation methods of the sealing behavior are proposed in the North America and Europe independently. One of the problems is that the representations of the sealing behavior are rather complex in both the methods. Thus, gasket tests take a long time to perform and cost much. The authors have carried out investigations on the sealing behavior of compressed fiber sheet gaskets and have shown that the leak rate is uniquely determined by the compressive strain of gasket. This fact makes the test procedure much easier eliminating complex loading-unloading sequences. A simplified leak testing procedure, in which a simple one-way loading is employed, has proposed. Furthermore, an equation for the sealing behavior of gasket, in which the effect of dimensions of gaskets is taken into consideration, has proposed. In this study, investigations on the sealing behaviors are overviewed first. Then, it is shown that the conventional sealing behavior based on the gasket stress is easily obtained from the sealing behavior based on the gasket strain and the stress-strain diagram of gasket. Both the sealing behavior and the stress-strain diagram of gasket are expressed by equations in this method. Finally, it has also shown that the sealing behavior obtained by the simplified test can be fully converted to the ROTT (ROom Temperature Tightness Test) forms.
Stress-strain relationships in yarns subjected to rapid impact loading: 1. Equipment, testing procedure, and typical results
