This method is designed to evaluate the coking propensity of synthetic ester-based aviation lubricants under single phase flow conditions found in certain parts of gas turbine engines, for instance in bearing feed tubes. This method is applicable to lubricants with a coking propensity, as determined by this method, falling in the range 0.01 to 3.00 mg.
The tendency of a lubricant to form deposits in an engine oil system is a critical factor that can influence engine design, performance and maintenance intervals. Therefore, it is important to have an understanding of the coking propensity of the lubricant. The ARP has been revised to make the method more applicable to the use of more modern instruments and to introduce a procedure for extending the test for a further 20 hour period.