US Patent 11149859 Close only expansive gate valve

A system, including a first flow control element configured to couple to a stem, and a second flow control element coupled to the first flow control element, wherein the first and second flow control elements are configured to expand relative to one another to create a seal in a closed position between a chamber and a flow path in a valve body, and wherein the first and second flow control elements are configured to enable fluid flow between the chamber and the flow path in an open position.