Patent ID: 8430628

Claim:
A pressure balance seal positioned within an annular cavity of a stator comprising a first stator element and a second stator element, the pressure balance seal comprising: a sealing surface facing an inward radial direction; a stator interface comprising at least one surface interfacing with the stator; a friction reducing feature comprising a cavity on the sealing surface, the cavity configured to receive a fluid, such that a normal force acting on the pressure balance seal is counterbalanced by a force generated by a pressure of the fluid, wherein the friction reducing feature permits a fluid to move from at least one higher pressure region adjacent to at least one portion of the stator interface to at least one lower pressure region adjacent to the sealing surface, and thereby reduce the normal force on the pressure balance seal; and a profile created on the pressure balance seal, the profile configured to reduce a possibility of twisting of the pressure balance seal.