The invention is an elongated valved device adapted to be coupled between a string of tubing and a well bore packer.An outer sleeve is coupled at one end to the tubing and has a movable hollow mandrel into the other end of the outer sleeve. Advancing or retracting of the mandrel is afforded by rotating the mandrel to engage grooves in the periphery of the mandrel with lugs at the end of the outer sleeve, then moving the mandrel axially with respect to the outer sleeve.An inner sleeve is locked in position within the outer sleeve and has a spring loaded flapper valve assembly at its end facing the end of the mandrel.Advancement of the mandrel forces its end (curved) through the valve assembly.