An apparatus, system and method relating to a valve assembly for use in a subterranean well for oil, gas, or other hydrocarbons. The valve assembly comprises an engaging element with a resilient portion having a first shape when a first pressure differential is applied across the engaging element in a direction and a second shape when a second pressure differential is applied across the element in the direction; a receiving element having sealing section; wherein the engaging element is engagable with the first receiving element to substantially prevent the flow of fluids through the sealing section a pressure differential is applied to the engaging element that is less than a first pressure differential; wherein the engaging element is extrudable through the first receiving element by applying a second pressure differential that is greater than the first pressure differential.