Intended for use as a high capacity liquid withdrawal valve with a manual shut off device in LPG or NH3 containers. These valves are equipped with an integrated excess flow feature that is internal to the container. The ME671IBC is equipped with an integrated back check (IBC) feature built into the lower portion of the seat disc assembly. This feature allows liquid pressure built upstream of the shut-off disc assembly to automatically be relieved back to the container when line pressures exceed 10-25 PSI over container pressure. The (IBC) feature eliminates the need for hydrostatic relief valves to protect upstream piping or lines as well as greatly reducing product emissions and overall system safety.