Apr 25, 2018
Ductile Iron Pipe is sized based on some dimensionless expression called the Pipe Size or Nominal Diameter (known by its French abbreviation, DN). This is approximately equal to the pipe's inner diameter in inches or millimeters. But, it's the outside diameter of the Tyton Joint Ductile Iron Pipe that's kept steady between fluctuations in wall thickness, so as to keep compatibility in fittings and joints. As a result, the inner diameter fluctuates, sometimes considerably, from its minimal size. Nominal pipe sizes range from 3 inches up to 64 inches, in increments of 1 inch, in the USA. Although both metric, both Australian and European aren't compatible and plumbing of indistinguishable nominal diameters have very different measurements.