1.1 ,This specification covers coextruded composite drain, waste, and vent pipe (DWV). The pipe is produced in Schedule 40 IPS sizes by a coextrusion die system, in which the concentric layers are formed and combined before exiting the die.
1.1.1 ,Coextruded composite drain, waste, and vent pipe, DWV, by definition, is permitted to be produced with two or more layers. The outer layer shall be ABS. The middle layer is permitted to be thermally foamed PVC or solid PVC or a blend of rework material, as specified in the rework material section. The inner layer is permitted to be solid PVC or ABS, or a blend of rework material as specified in the rework material section.