WRC 339:1988
$23.40
Development of Tightness Test Procedures for Gaskets in Elevated Temperature Service
Published By | Publication Date | Number of Pages |
WRC | 1988 | 26 |
Following extensive investigation of room temperature behavior of gaskets, interest is now focusing on their elevated temperature performance particularly since the many new materials now available are not as stable at elevated temperature as asbestos products. An elevated temperature tightness test machine developed by the authors has been successfully used on a number of gasket materials and results indicate that an elevated temperature test must be run over a period of days or weeks in order for the time/temperature effects to be meaningful. The objective was, therefore, to develop alternate test methods which would reduce the test time on the tightness test machine yet yield comparable results.
In this report, different elevated temperature gasket tightness test procedures are compared. A two-tier test approach, involving aging of the preloaded gasket in a kiln, followed by a short duration tightness test is shown to give the same results as a tightness of the same overall duration at the same temperature on a virgin gasket. The effect of cumulative gasket deflection on tightness performance is discussed. The procedures were evaluated using spiralwound gaskets with two different fillers: a mica-graphite filler and an asbestos filler. Results show that the two-tier approach is effective and offers a wide range of possibilities including long term aging at temperatures beyond the limits of the tightness test machine.