This specification describes an apparatus for carrying out a method of making a multi-walled pipe in the shape of a tube having a helical configuration. The apparatus is made up of an extruder with multiple dies. These multiple dies include at least two concentric arcuate dies that are radially spaced apart and a plurality of relatively straight dies that radially connect the concentric arcuate dies. The apparatus includes means for cooling the extrudate to solidify it into a usable condition. Means are provided to cause the multi-wall pipe to have a helical configuration, that is, apparatus is provided that arranges the pipe as a whole into a structure that has a circumferential component and a longitudinal component to its orientation; e.g. a helix. The longitudinal orientation is accomplished by providing apparatus that causes the pipe to proceed downstream in the direction of its longitudinal axis. In one embodiment of this invention, the extrudate is pulled longitudinally down stream. The circumferential component of the orientation of the multi-walled pipe can be accomplished by either one of two apparatus elements. First, the extrudate can be twisted (that is rotated circumferentially while it is being pulled down stream). This can be accomplished with a single piece of apparatus as shown. Thus, a longitudinal and a circumferential movement can be applied to the molten extrudate by twisting the solidified extrudate downstream of the cooling apparatus. This same configuration can be accomplished by extruding the multi-walled pipe through rotating dies whereby the extrudate is given a circumferential orientation even before it emerges from the extruder die and the circumferentially rotated pipe can then be longitudinally pulled downstream.