The fabricator of extruded PVC pipe has several important criteria. Most significant is that extrusion lines run continuously at optimum output of acceptable product of very closely controlled dimensions. There should almost never be an interruption from equipment failure and certainly never one caused by compound degradation. “Acceptable” in this sense, denotes that the formulation and the product are acceptable to the National Sanitation Foundation (U.S) or similar regulatory agency, in terms of ingredients and properties, either for potable or nonpotable water categories.