An expanding gate valve assembly includes a segment and a gate Inner faces of the segment and gate are configured for slidable contact and angled faces of the segment and gate are configured for slidable contact to form a first gate assembly interface. The first gate assembly interface can further include a tab on the gate configured to contact a base surface of the segment to form a second gate assembly interface. A spring can be coupled between the gate and the segment to maintain at least the first gate assembly interface. The tab can be disposed below the segment to provide a lifting engagement with the base surface of the segment. The first gate assembly interface can be ledge-free.