A self-aligning valve assembly and a valve plug therefor includes an elastomeric valve plug having an annular outer sealing portion with an annular sealing surface for sealing a drain hole valve seating of a receptacle. A central mounting portion is secured to a pair of telescoped tubes. A flexible diaphragm...http://www.google.fr/patents/US4338689?utm_source=gb-gplus-shareBrevet US4338689 - Self-aligning valve assembly
