Patent ID: 8727312

Claim:
A butterfly valve disk assembly comprising: a disk member having a first surface disposed about a periphery having a first diameter, the disk member having a second surface offset from the first surface, the disk member having an inlet side and an outlet side, the second surface being on the inlet side; a seal ring arranged adjacent the first surface, the seal ring having a first outer surface with a second diameter, wherein the second diameter is larger than the first diameter; and, a retainer coupled to the second surface adjacent the seal ring opposite the first surface, the retainer having an inner surface, wherein the inner surface is arranged to radially constrain the seal ring on the disk member; wherein the disk member includes a groove disposed adjacent the first surface and at least a portion of the seal ring is disposed within the groove; wherein the retainer is at least partially disposed within the groove; wherein the disk member includes a third surface offset from the second surface distal from the first surface; and wherein the retainer includes a first projection distal from the second surface, the first projection engaging the third surface.