VISUALIZATION IN THE INTERFACE OF A NONCONTACTING MECHANICAL FACE SEAL WITH SPIRAL GROOVE PATTERN

A noncontacting mechanical face seal with spiral groove pattern had been designed and tested under relatively low pressures by means of visualization in its interface. The visualizations not only demonstrated its principle of operation, but also revealed the successive stages of the fluid film formation from the start-up, transition state to dynamically stable operating condition. The tests also showed that for properly aligned seal faces, the generated fluid film was stable, ensuring lubrication around the interface and hence the noncontacting and zero leakage condition, whereas for misaligned seal faces, the fluid film was not uniform, resulting in leakage even at relatively high speeds.