A venous valve with a tubular frame that includes an outer surface and an inner surface opposite the outer surface and defining a lumen, and a cover over at least the outer surface of the tubular frame, where the cover includes surfaces defining a reversibly sealable opening for unidirectional flow of a liquid through the lumen. A system with the venous valve and a catheter including a proximal end and a distal end, the venous valve located between the proximal end and distal end of the catheter. A method including forming the venous valve and reversibly joining the venous valve and a catheter. A method including positioning at least part of the catheter including the venous valve at a predetermined location and deploying the venous valve from the catheter at the predetermined location.