What is the difference between nominal sizes according to DIN and NPS?
The nominal width DN is a dimensionless number that defines the inner diameter of a pipeline or the connection dimension of a fitting. The nominal diameter DN indicates the approximate inner diameter of the pipeline in millimetres and is based on the metric system of measurement.
The designation Nominal Pipe Size, also called NPS, also quantifies the inner diameter of a pipeline or the connection dimension of a fitting. In this definition, too, the approximate inner diameter of the pipeline is named, but the information is given in inches, which originates from the Anglo-American system of measurement.
Nominal size DN | NPS in Inch | Pipe connection ISO | Pipe connection EN |
DN 6 | 1/8“ | Ø 10,2 mm | Ø 10,2 mm |
DN 8 | 1/4“ | Ø 13,5 mm | Ø 13,5 mm |
DN 10 | 3/8“ | Ø 17,2 mm | Ø 17,2 mm |
DN 15 | 1/2“ | Ø 21,3 mm | Ø 21,3 mm |
DN 20 | 3/4“ | Ø 26,9 mm | Ø 26,9 mm |
DN 25 | 1“ | Ø 33,7 mm | Ø 33,7 mm |
DN 32 | 1 1/4" | Ø 42,4 mm | Ø 42,4 mm |
DN 40 | 1 1/2" | Ø 48,3 mm | Ø 48,3 mm |
DN 50 | 2“ | Ø 60,3 mm | Ø 60,3 mm |
DN 65 | 2 1/2" | Ø 76,1 mm | Ø 76,1 mm |
DN 80 | 3“ | Ø 88,9 mm | Ø 88,9 mm |
DN 100 | 4“ | Ø 114,3 mm | Ø 114,3 mm |
DN 125 | 5“ | Ø 139,7 mm | Ø 139,7 mm |
DN 150 | 6“ | Ø 168,3 mm | Ø 168,3 mm |
DN 200 | 8“ | Ø 219,1 mm | Ø 219,1 mm |
DN 250 | 10“ | Ø 273,0 mm | Ø 273,0 mm |
DN 300 | 12“ | Ø 323,9 mm | Ø 323,9 mm |
DN 350 | 14“ | Ø 355,6 mm | Ø 355,6 mm |
DN 400 | 16“ | Ø 406,4 mm | Ø 406,4 mm |
DN 450 | 18“ | Ø 457,0 mm | Ø 457,0 mm |
DN 500 | 20“ | Ø 508,0 mm | Ø 508,0 mm |
DN 600 | 24“ | Ø 610,0 mm | Ø 610,0 mm |
DN 700 | 28“ | Ø 711,0 mm | Ø 711,0 mm |
DN 800 | 32“ | Ø 813,0 mm | Ø 813,0 mm |
DN 900 | 36“ | Ø 914,0 mm | Ø 914,0 mm |
DN 1000 | 40“ | Ø 1016,0 mm | Ø 1016,0 mm |
DN 1200 | 48“ | Ø 1220,0 mm | Ø 1219,0 mm |
DN 1400 | 56“ | Ø 1420,0 mm | Ø 1422,0 mm |
DN 1600 | 64“ | Ø 1620,0 mm | Ø 1626,0 mm |
DN 1800 | 72“ | Ø 1820,0 mm | Ø 1829,0 mm |
DN 2000 | 80“ | Ø 2020,0 mm | Ø 2032,0 mm |
DN 2200 | 88“ | Ø 2220,0 mm | Ø 2235,0 mm |
DN 2400 | 96“ | Ø 2420,0 mm | Ø 2438,0 mm |
DN 2600 | 104“ | Ø 2620,0 mm | Ø 2620,0 mm |
DN 2800 | 112“ | Ø 2820,0 mm | Ø 2820,0 mm |
DN 3000 | 120“ | Ø 3020,0 mm | Ø 3020,0 mm |
DN 3200 | 128“ | Ø 3220,0 mm | Ø 3220,0 mm |
DN 3400 | 136“ | Ø 3420,0 mm | Ø 3420,0 mm |
DN 3600 | 144“ | Ø 3620,0 mm | Ø 3620,0 mm |
