The tightness of a flanged joint in operation generally depends on the stress acting on the gasket - assuming that the choice of the gasket is correct. For the correct choice of the gasket all relevant deformation charcteristics, tightness characteristics and the long term behaviour must be known for every possible operating condition (including assembly). These characteristics have to be described by a set of gasket factors. The stress acting on the gasket depends on operation loads (e.g. internal pressure, temperature, forces and moments), gasket characteristics (e.g. deformation in loading and unloading direction, relaxation), design/construction of the joint (e.g. stiffness) and last but not least the assembly/mounting procedure. Only if each one of these parameters is known exactly, tightness of a flanged joint can be proofed and guaranteed. Within this task it is necessary to have an accurate calculation method, which allows the evaluation of the resulting stress on the gasket regarding every parameter above. This is even true with standardized flanged joints. This paper gives an overview over the relations in bolted joints. The most important gasket factors are discussed, the procedure for a tightness proof is provided and a reliable prestressing method is shown.
展开▼
