Patent ID: 7097176
Filing Date: 2006-08-29
Classification: F16J

Abstract:
1. A mechanical seal for mounting to a housing containing a rotating shaft, said mechanical seal comprising: a single rotatable seal ring having a pair of concentric seal faces to form a radially inner seal face and a radially outer seal face, said rotatable seal ring having an axially extending passage formed therein for allowing passage of a barrier fluid therethrough, first and second stationary seal rings, each having a seal face, wherein the seal face of the first stationary seal ring contacts the radially outer seal face of the rotatable seal ring and the seal face of the second stationary seal ring contacts the radially inner seal face of the rotatable seal ring, a sleeve adapted to be mounted about the rotating shaft and rotatably coupled thereto and to the rotatable seal ring, said sleeve having a flange portion that is configured for housing at least a portion of the rotatable seal ring, and a gland for housing at least partially the single rotary seal ring and the first and second stationary seal rings, wherein the rotatable seal ring and the first and second stationary seal rings are configured and arranged to provide for first and second piston areas on a face wall of the rotatable seal ring adjacent an inner surface of the flange that allow the barrier fluid to exert pressure across a selected portion that is between about 50% and about 140% of the contact area of the seal face contact areas.