1 inch = 25.4mm = 8 English
1/2 is four points (4 points) dn15
3/4 is six points (6 points) dn20
2 In Charge Of dn8
4 In Charge Of dn15
6 In Charge Of dn20
1' dn25
1.2 'dn32
1.5 'dn40
2' dn50
2.5 'dn65
3' dn80
4' dn100
5' dn125
6' dn150
8' dn200
10' dn250
12' dn300
GB/T50106-2001
2.4 diameter
2.4.1 The diameter should be mm.
2.4.2 the expressions of pipe diameter shall comply with the following provisions:
1 Water Gas Transmission Pipe (galvanized or non-galvanized), Cast Iron Pipe and other pipes, the diameter should be indicated by nominal diameter DN;
2 seamless steel pipe, welded steel pipe (straight or spiral), copper pipe, stainless steel pipe and other pipes, the diameter should be expressed in the outer diameter × wall thickness;
3 reinforced concrete (or concrete) pipes, clay pipes, acid-proof ceramic tubes, cylinder and tile tubes, etc., the diameter should be indicated by the diameter d;
4 plastic pipe, pipe diameter should be expressed according to the product standard;
5. When the design uses the nominal diameter DN to indicate the pipe diameter, the nominal diameter DN should be compared with the corresponding product specifications.
De (nominal outer diameter) x e (nominal wall thickness) (GB 5836.1-92)
Polypropylene (PP) pipe specifications for water supply are expressed by De × E (nominal outer diameter × wall thickness)
