Pipe Sizes and Tolerances

Pipe Sizes and Tolerances​ Nominal Pipe Sizes (NPS) Steel pipe sizes are based on historical dimensions called Nominal Pipe Sizes (NPS) which standardize the nominal outside diameter (OD). Additionally, a series of standard wall thicknesses known as Schedules (SCH) was also developed years ago. The units for both NPS and SCH are dimensionless. A larger […]