SCHEDULE, PIPE

A means of indicating the wall thickness of pipe sizes, as set forth in ASME B36.1 and ASTM A530 and B775. Commonly available pipe schedules are Schedules 5, 10, 20, 40, and 80.

The actual wall thickness of a schedule number varies with the nominal pipe size or diameter (e.g.: 0.5" Sch 40=0.109" while 2" Sch 40=0.154"). A higher number schedule indicates a thicker wall for a particular pipe diameter.