It is well known that an axial bolt force which tightens a gasket decreases due to a creep of non-asbestos gaskets. A bolted flange joint contains a combined condition of the creep/relaxation. A reduction behavior of a tightening pressure due to an effect of creep/relaxation is related to lifetime assessment of the non-asbestos gasket, and a leakage prevention of internal fluid. In this research, the creep/relaxation of the bolted flange joint using the non-asbestos gasket is measured. The compressed creep test is carried out using four-inch flanges and non-asbestos compressed fiber sheet gaskets. The test conditions are room temperature and 90 hours. The result of creep/relaxation is evaluated by 3-D viscoelasticity model. The creep/relaxation that was evaluated by 3-D viscoelasticity model and the Young’s modulus of the non-asbestos gaskets that was measured by the nanoindentation testing is applied to the FE analysis. FE model that include viscoelasticity is 1/16 of the test device. The stress state of the non-asbestos gasket was confirmed by the FE analysis. Then, the validity of creep/relaxation of the non-asbestos gaskets that was evaluated by the 3-D viscoelasticity model was shown by comparison with the experimental value and the analysis result.

This content is only available via PDF.
You do not currently have access to this content.