In accordance with the present invention, a container outlet valve assembly (10) is provided including a generally cone-shaped housing (12) extending upwardly into the container, and including radially spaced openings (14) in the housing for lading to flow out of the container. A cone valve (30) is located within the housing containing spaced openings (34) which align with the openings (14) in the cone housing when the cone valve is in open position. A liner (36) of low friction material is attached to the outer surface of the cone valve and/or the inner surface of the cone housing. The cone valve is rotatable to a closed position in which the valve body closes the openings located in the housing (FIG. 3). An unloading chamber (44) is located below the cone valve and is attached to a tank mounting flange (18) with shearable fasteners (24). The flange does not extend below the tank bottom in excess of one (1) inch. In one embodiment (FIG. 1) an operating shaft (64) for the cone valve extends up through the unloading spout and engages a connection portion (84) formed in the upper, inner surface of the cone valve.