Flange tables

Flanges are used to connect valves into pipework, making maintenance and removal easier. Their standards vary worldwide and can not always be interchangeable. The tables below show PN flange dimensions to help you identify the standards that you have.

Nominal pressure Flange diameter (mm) PCD (mm) No. of bolt holes Diameter of bolts Diameter of holes (mm) Diameter of raised face (mm) Height of raised face (mm)
1/2″ nominal bore (DN15)
PN6 80 55 4 M10 11 40 2
PN10 95 65 4 M12 14 45 2
PN16 95 65 4 M12 14 45 2
PN25 95 65 4 M12 14 45 2
3/4″ nominal bore (DN20)
PN6 90 65 4 M10 11 50 2
PN10 105 75 4 M12 14 58 2
PN16 105 75 4 M12 14 58 2
PN25 105 75 4 M12 14 58 2
1″ nominal bore (DN25)
PN6 100 75 4 M10 11 60 2
PN10 115 85 4 M12 14 68 2
PN16 115 85 4 M12 14 68 2
PN25 115 85 4 M12 14 68 2
1 1/4″ nominal bore (DN32)
PN6 120 90 4 M12 14 70 2
PN10 140 100 4 M16 18 78 2
PN16 140 100 4 M16 18 78 2
PN25 140 100 4 M16 18 78 2
1 1/2″ nominal bore (DN40)
PN6 130 100 4 M12 14 80 3
PN10 150 110 4 M16 18 88 3
PN16 150 110 4 M16 18 88 3
PN25 150 110 4 M16 18 88 3
2″ nominal bore (DN50)
PN6 140 110 4 M12 14 90 3
PN10 165 125 4 M16 18 102 3
PN16 165 125 4 M16 18 102 3
PN25 165 125 4 M16 18 102 3
2 1/2″ nominal bore (DN65)
PN6 160 130 4 M14 14 110 3
PN10 185 145 4 M18 18 122 3
PN16 185 145 4 M18 18 122 3
PN25 185 145 8 M18 18 122 3
3″ nominal bore (DN80)
PN6 190 150 4 M16 18 128 3
PN10 200 160 8 M16 18 138 3
PN16 200 160 8 M16 18 138 3
PN25 200 160 8 M16 18 138 3
4″ nominal bore (DN100)
PN6 210 170 4 M16 18 148 3
PN10 220 180 8 M16 18 158 3
PN16 220 180 8 M16 18 158 3
PN25 235 180 8 M20 22 162 3
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