Abstract: A truck tank to be carried in the bed of a pickup truck equipped with a bed-mounted hitch. The tank is profiled to fit within the wheel wells of the truck bed and to have either an arched recess formed in the bottom to accommodate the hitch when the tank is lifted into the bed or alternatively, an arched groove extending from the arched recess to the side of the tank so as to permit the tank to be slid into the truck bed.

Abstract: Locking apparatus is mounted to a wall or inside a bag-supporting container. The fluid-storage bag has a tubular fitting with axially spaced flanges forming an annular locking area. The locking apparatus comprises a diaphragm mounted over a port formed in the wall. The diaphragm has a opening formed therein which has a size and polygonal profile which matches the polygonal perimeter of the fitting's locking area. Cuts extending radially from the vertices of the polygonal opening form radial flaps. The outermost flange is larger than the diaphragm opening and when forcibly pushed through the diaphragm opening it deflects the flaps. Once the outermost flange passes axially through the flaps, the flaps snap back flexibly and engage the fittings locking area, resisting fitting removal. The complementary polygonal tubular perimeter and diaphragm opening resist rotation aiding in installation of threaded accessories.