Abstract: An apparatus for containing and conducting flowable materials, including liquids, pourable solids, or gases, the apparatus having mateable dovetails on four sides, and mateable screw engagements at the top and bottom. The screw engagements are operative to maintain a sealed connection between successive containers, and contain barriers which are adapted to be removed, whereby the material may flow from one interconnected container to the next, in the manner of piping. A lateral connection may additionally be formed by mating portions at the leading and trailing ends of vertically connected containers.