Nominal inner diameter and corresponding outer diameter of galvanized pipe

1. Nominal inner diameter and corresponding outer diameter:
- DN15: The nominal inner diameter is 15 mm, and the corresponding outer diameter is 21.3 mm.
- DN20: The nominal inner diameter is 20 mm, and the outer diameter is 26.9 mm.
- DN25: The nominal inner diameter is 25 mm, and the outer diameter is 33.7 mm.
- DN32: The nominal inner diameter is 32 mm, and the outer diameter is 42.3 mm (some also say 42.25 mm).
- DN40: The nominal inner diameter is 40 mm, and the outer diameter is 48.3 mm.
- DN50: The nominal inner diameter is 50 mm, and the outer diameter is 60 mm.
- DN65: The nominal inner diameter is 65 mm, and the outer diameter is 76.1 mm.
- DN80: The nominal inner diameter is 80 mm, and the outer diameter is 88.9 mm.
- DN100: nominal inner diameter is 100 mm, outer diameter is 114.3 mm.
- DN125: nominal inner diameter is 125 mm, outer diameter is 140 mm.
- DN150: nominal inner diameter is 150 mm, outer diameter is 168.3 mm.
- DN200: nominal inner diameter is 200 mm, outer diameter is 219.1 mm.

2. Wall thickness: galvanized pipes with different nominal inner diameters have different wall thicknesses. For example, small-sized galvanized pipes such as DN15 generally have thinner wall thicknesses, which may be around 2 mm; medium-sized galvanized pipes such as DN50-DN100 usually have wall thicknesses of 3-4 mm; large-sized pipes such as DN150 and above may have wall thicknesses of 4.5 mm and above. The specific wall thickness will vary according to different production standards, usage requirements, etc.