Method for the evaluation of elastomeric seals by compression stress relaxation

A method is described whereby elastomer O-ring performance can be evaluated by compression stress relaxation in a simulated gas turbine lubrication system. The O-ring retained sealing force is measured in real-time during high temperature ageing and during transients to lower temperatures, thus simulating the temperature regimes experienced in an operational gas turbine. In addition to this, the O-rings are exposed to a flow of realistically aged turbine lubricant, producing a realistic level of chemical degradation during testing. The results from this work have demonstrated significant differences between elastomer behaviour due to O-ring material and also due to the temperature regimes subjected to during compression stress relaxation. Taken as a whole, this work represents a considerable improvement on current elastomer O-ring test methods as applied to gas turbine lubricant system seals.