Butterfly valve plate sealing assemblies are provided that include a sealing ring and a retention spacer disposed at least partially within a sealing ring groove formed about a periphery of a butterfly valve plate. The sealing ring includes a first portion, a second portion configured substantially perpendicular to the first portion, and a substantially L-shaped cross-section. The sealing ring is positioned at least partially within a groove opening and a groove body defining the sealing ring groove. The retention spacer is positioned at least partially within the groove opening and adjacent the first portion of the sealing ring. The retention spacer is configured to limit expansion of the sealing ring when under the influence of a pressurized fluid flow. The second portion of the sealing ring may be configured to optimize stiffness for a desired sealing ring tension.