Knowledge of the taper angle of the lubricating film of a rotary mechanical seal is fundamental to understanding seal performance. Whilst the literature contains numerous reports of mechanical seal distortion analysis, these usually deal with specific seal designs. This paper addresses the analysis procedures more generally, giving a detailed discussion of factors affecting prediction of seal ring distortions, especially heat partitioning, locating reaction diameters and estimation of heat transfer coefficients. The “face locking” concept is discussed. Use of influence coefficients is discussed and an extension of this concept for distributed interfacial pressure is presented. Finally a typical analysis sequence is outlined.Presented at the 45th Annual Meeting In Denver, Colorado May 7–10, 1990