Stem seal

摘要

A valve stem seal comprising a cylindrical stem-sealing membranes 6 and a membrane supporting flange 7. The membrane has a corrugated profile which defines on or more loop-shaped channels 11 bounded by contact surfaces 13 on a radially inner face and each channel is inclined at 5 DEG -10 DEG with respect to a plane perpendicular to the longitudinal axis. The channels form a labyrinth seal for any fluid leaking along the outer surface of the stem. A support bearing 8 for the stem is provided on the membrane supporting flange. <IMAGE>