Abstract
Asbestos fiber gaskets had widely been used in bolted flange connections of piping systems in chemical plants, oil refinery plants, power plants and so on. However, the use of asbestos fiber gaskets has already been prohibited due to the health problems caused by the asbestos fibers. As substitutes for the asbestos fiber gaskets, non-asbestos gaskets, such as aramid fiber-based, expanded graphite-based and PTFE-based, have been developed by gasket manufacturers and they are in use. Contrary to the superior heat-resisting properties of the asbestos fiber gaskets, the thermal resistances of some of the non-asbestos gaskets are not high enough. The thermal resistances of non-asbestos fiber gaskets do not satisfy the demands of gasket users. This is a serious problem especially in the high temperature applications for low nominal pressure rating flanged connections. One of the solutions is to apply spiral wound gaskets to flanged connections instead of sheet gaskets. It is not a common practice to use spiral wound gaskets for low nominal pressure rating flanged connections as spiral wound gaskets normally require high bolt loads. However, spiral wound gaskets might be used in low nominal pressure flanged connections as the sealing performance of newly developed spiral wound gaskets is quite high.
In this paper, the sealing performance of sheet gaskets and spiral wound gaskets are tested under the same loading condition. Both the sealing performances are compared and discussions are made. It is found that the sealing performances of spiral wound gaskets are superior to those of sheet gaskets under the same gasket load. Thus, the spiral wound gaskets can be applied to low nominal pressure rating flanged connections as substitutes for sheet gaskets.
