Abstract: A hinge assembly to pivotably mount a blind flange to a weld neck flange includes a front assembly having a front plate and a plurality of front link plates coupled to the front plate, the front plate having a plurality of openings, each opening in the front plate coupled to mechanical fasteners to secure the front plate to the blind flange, a rear assembly pivotably mounted to the front assembly and having a rear plate and a plurality of rear link plates coupled to the rear plate, the rear plate having a plurality of openings, each opening in the rear plate coupled to mechanical fasteners to secure the rear plate to the weld neck flange, each front link plate disposed between a pair of adjacent rear link plates, and a pin disposed through each front link plate and the pair of adjacent rear link plates.