The Conversion Relation For Pipes, Threads And Nominal Diameter

    Normally the diameter of the piping can be classified as outer diameter, inner diameter,and nominal diameter. The outer diameter of seamless piping is shown as D added with outer diameter dimension and wall thickness. For example, seamless piping of outer diameter 108 mm, wall thickness 5mm, shown as D108*5. Or adopting DN (Nominal diameter). Nominal diameter is specified for the design and maintenance,and is the name for pipes. Below is the conversion relation for pipes, threads and nominal diameter.