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This paper will discuss the background and concerns over the permeation of elastomer seals. Comparisons will be made between the permeation of materials and the permeation of components. Specific configurations used will be discussed in relation to test methodology and how it relates to sealing applications. It will show how the results of gravimetric weight loss tests compare to results obtained by speciation and mini-SHED testing. It will provide a perspective of the importance of developing good techniques to measure permeation, and how it is useful to validate procedures across test methods and understand what is happening, rather than just “running the test”.

If the amount of sealing force and its retention are a primary criteria used for estimating and predicting the capability of compressive seals, it is important to understand how configurations used in testing and in applications can affect the sealing response of materials. If Compression Stress Relaxation (CSR) testing is to be of value for validation of capability and for specification purposes, different test configurations must provide the same values, and the values determined, should be relevant to the actual applications. It is important to separate material capability from configuration effects to optimize the performance of a material in compressive seals. In this paper, sealing force response was evaluated in different configurations and under different test variable conditions.

Micro-SHED (Sealed Housing Emissions Determination) test results of various fuel hoses are compared to the theoretical model predictions of the hose hydrocarbon emissions. Theoretical prediction of the hydrocarbon emission for a defined hose construction is derived from the permeation constants of the materials used in these constructions. Total evaporative emission ET for a fuel hose is considered to originate from three sources: (1) emission through the wall Ew, (2) emission through the ends EE and (3) emission from leaks EL so that Results of this investigation show that, for a specific hose construction, reasonable predictions of hose micro-SHED test results can be made.