Abstract
Some gaskets are used in many device, for example, rotary compressor, valve and so on. The device is inspected and internal parts of gaskets etc. are exchanged periodically. The time cycle for inspection and exchange that have decided empirically before.
It has decided not to understand the exact life time for some gaskets. So, at this time, we tested for the compressed asbestos fibers sheet gaskets (CAF) on the temperature of 200°C. As the results, we tried to estimate and made sure of the life time more exactly for CAF. The temperature of 200°C which we adopted is severe than the used temperature in fact.
The life time for CAF is estimated about 18 years on 200°C.
We had been tested relaxation and seal performance for metal gaskets before. So we confirmed to be able to estimate the life time with the results of both.
It is possible that we estimate the life time for CAF and the other non-asbestos gaskets, too, with the results of as same as metal gaskets.
But we can't consider effects of bolt stress and pipe stress at this time. The life time for CAF is expected to be shorten than 18 years in fact. There need to examine more totally for bolted flanged joint in future. So we are going to confirm for these effects with finite element method etc.
