To determine the correct size of PVC pipe for a project, use a pipe size chart to determine the pipe size that fits the supply line. The size chart can be used on the pipe that is being replaced, or can be matched at a home improvement store.
A printable PVC pipe size guide is available on FormUFit.com as of April 2015. From the FormUFit.com home page, place the cursor over PVC Projects. On the drop-down menu that appears, place the cursor over How-To Guides, and click on PVC Size Guide on the subsequent menu. The guide can be opened or downloaded in PDF format. After printing the guide, place a nickel in the size scale to ensure the size is correct.
The inside diameter of PVC pipe is used for size measurements. The thickness of a PVC pipe wall is called the PVC Schedule, which is abbreviated to SCH. SCH 40 is the most common size, with SCH 80 and SCH 120 also common.
PVC pipe can be used as a cold water line, a gas line or a drain-waste-vent line. Consult local building codes and regulations before installing PVC pipe. When used as a gas line, PVC pipe must be used underground only.