All dimensions are in "mm" unless noted otherwise.

Dimensions of Class 150 RF Weld Neck Flanges as per ASME B16.5.

Weld Neck Flange

Nominal
Pipe Size
Outside Dia
of Flange
(O)
Thick of
Flange
(C)
Dia of
Raised Face
(R)
Dia of
Hub at Base
(X)
Dia of
Hub at End
(A)
Length
thru Hub
(V)
No of
Holes
Dia of
Holes
(H)
Dia of
Bolts
Dia of
Bolt Circle
(B)
Approx
weight
(kg)
1/2 88.9 11.2 35.1 30.2 21.3 47.8 4 15.7 1/2 60.5 1
3/4 98.6 12.7 42.9 38.1 26.7 52.3 4 15.7 1/2 69.9 1
1 108 14.2 50.8 49.3 33.5 55.6 4 15.7 1/2 79.2 1
1-1/4 117.3 15.7 63.5 58.7 42.2 57.2 4 15.7 1/2 88.9 1
1-1/2 127 17.5 73.2 65 48.3 62 4 15.7 1/2 98.6 2
2 152.4 19.1 91.9 77.7 60.5 63.5 4 19.1 5/8 120.7 3
2-1/2 177.8 22.4 104.6 90.4 73.2 69.9 4 19.1 5/8 139.7 4
3 190.5 23.9 127 108 88.9 69.9 4 19.1 5/8 152.4 5
3-1/2 215.9 23.9 139.7 122.2 101.6 71.4 8 19.1 5/8 177.8 5
4 228.6 23.9 157.2 134.9 114.3 76.2 8 19.1 5/8 190.5 7
5 254 23.9 185.7 163.6 141.2 88.9 8 22.4 3/4 215.9 9
6 279.4 25.4 215.9 192 168.4 88.9 8 22.4 3/4 241.3 11
8 342.9 28.4 269.7 246.1 219.2 101.6 8 22.4 3/4 298.5 18
10 406.4 30.2 323.9 304.8 273.1 101.6 12 25.4 7/8 362 24
12 482.6 31.8 381 365.3 323.9 114.3 12 25.4 7/8 431.8 36
14 533.4 35.1 421.8 400.1 355.6 127 12 28.4 1 476.3 50
16 596.6 36.6 469.9 457.2 406.4 127 16 28.4 1 539.8 64
18 635 39.6 533.4 505 457.2 139.7 16 31.8 1-1/8 577.9 68
20 698.5 42.9 584.2 558.8 508 144.5 20 31.8 1-1/8 635 82
24 812.8 47.8 692.2 663.4 609.6 152.4 20 35.1 1-1/4 749.3 118