O-Ring Permeation Measurements for Selected Pressures and Gland Designs 670565
Measurements were made of helium permeation rates for O-rings subjected to helium pressure on one side and vacuum on the other. Helium pressures up to 1000 psi were used in the investigation. Gland designs included grooves for O-ring squeezes from 25 to 75 percent, dual O-ring grooves, and two tongue-and-groove configurations.
Calculations were made of the expected permeation rates based on material permeability data. The results of this study indicate that dual O-rings and close-fitting tongue-and-groove designs provide permeation rates that are lower than the rates that are calculated by conventional methods.