Experimental characterisation of leak through elastomer-metal interface

Abstract

Elastomeric seals are devices that are widely used to prevent fluid leakage through the interface of mating parts. In this paper, we study the leak characteristics of a representative elastomeric seal system using an experimental setup that has been developed to measure the leak rate of gas through an elastomer-metal interface as a function of sealing load intensity and fluid pressure. These experiments are carried out on nitrile butadiene rubber (NBR), hydrogenated nitrile butadiene rubber (HNBR) and fluoro-elastomer (FKM) specimens using nitrogen gas at pressures ranging from 40 kPa to 800 kPa. The experiments revealed that the leak rate increases rapidly with gas pressure and decreases with sealing load intensity. When leak rate was plotted against normalised gas pressure, it was observed that all the data points fall reasonably on one single curve irrespective of sealing load intensity and the material. These results will be useful for further analysis in developing a mathematical model for characterising fluid leak through elastomer-metal alloy interfaces.