Analyses and predicted performance of a 50-mm diameter, spiral-groove face seal to seal liquid oxygen at 5.17 MPa pressure, and operating at surface speed of 183 mls are described. The pressure-balanced spiral-groove concept is introduced that circulates spiral-groove flow independent of leakage flow. Independent flow paths preclude overheating from vaporization and consequent flow blockage. The analysis accounts for fluid turbulence and inertia, thermoelastic distortions, and dynamic response. An operating-range map was developed as a function of speed and pressure. The fluid-film analysis is summarized in the Appendix.Presented at the 38th Annual Meeting in Houston, Texas, April 24–28, 1983