A stationary seal ring (270) is adapted to cooperate with a housing (265) and an impeller (85) to define a seal. The impeller is rotatable about an axis and includes a first seal portion (215) and a plurality of blades (150) that define an outside diameter. The stationary seal ring (270) includes an alignment surface (295) engageable with the housing (265) , and a plurality of teeth (320) . Each tooth (320) is spaced axially from an adjacent tooth to define a cavity (323) therebetween. Each tooth (320) includes a tooth tip (335) that cooperates with the first seal portion (215) to define a seal point. A first tooth (320) disposed nearest to the blades (150) has a first tip diameter. Each subsequent tooth has a tip diameter that is smaller than the first tip diameter.
