Technical FAQs

What's the difference between Schedule 40 and Schedule 80 PVC? (Plumbing)

The only difference between Schedule 40 & Schedule 80 is the wall thickness. The wall thickness also directly correlates with the pipe’s pressure rating. Schedule 40 (usually white) has a thinner wall thickness and therefore a lower pressure rating than Schedule 80 pipe (usually grey). Schedule 40 and 80 PVC pipe does not use the Outside Diameter / wall thickness ratio that DR and SDR use; therefore, the Schedule 40 and 80 pressure ratings are different for each pipe diameter size and must be looked up for every diameter and Schedule combination. Westlake Pipe & Fittings’ PVC Plumbing pipe (ASTM D1785) is available in both Schedule 40 and Schedule 80.