For Type I and II PVC and CPVC, 5/32" round rod when used with any of the 40s Series and FUSION Series welders. Applications for the KS-1 tip include the following: Electrical and computer enclosures; Plastic tanks and systems; Air handling equipment (fume hoods, ductwork, exhaust fans, blowers, fume scrubbers, mist eliminators, pollution control equipment); Chemical processing and waste treatment equipment; Piping, valves, fittings, elbows and tees; Chemical holding tanks and Solar cell processing equipment.