A downhole tool includes a tubular having an outer surface and an inner surface defining a flowbore having a longitudinal axis, and a backpressure valve cartridge arranged in the flowbore. The backpressure valve cartridge includes a valve seat and a flapper valve pivotally mounted relative to the valve seat. The backpressure valve cartridge is shiftable along the longitudinal axis to shift the flapper valve between a first position, wherein the flapper valve rests on the valve seat, and a second position, wherein the flapper valve is pivoted away from the valve seat.