Dimensions of Class 900 RF Orifice WN Flanges as per ASME B16.36.
Nominal Pipe Size, Diameter of Bolt Hole and Diameter of Stud Bolts are specified in inches.
All other dimensions are in "mm" unless noted otherwise.

Dimensions of Orifice WN Flanges

NPS
inch
OD
of
Flange
(O)
Dia
of
Raised
Face
(R)
Min
Thk
of
Flange
(T)
Weld
Neck
Length
(Y)
Hub
Dia
at
Base
(X)
Hub
Dia
at
End
(A)
Weld
Neck
Bore
(B)
Dia
of
Tap
(Tt)

Bolt
Circle

No.
of
Bolt
Holes
Dia
of
Bolt
Holes
Dia
of
Bolts
Stud
Bolt
Length
1 150 50.8 38.1 83 52 33.5 (1) 6.4 101.6 4 1 7/8 150
1-1/2 180 73 38.1 89 70 48.3 (1) 6.4 123.8 4 1-1/8 1 160
2 215 92.1 38.1 102 105 60.3 (1) 6.4 165.1 8 1 7/8 150
2-1/2 245 104.8 41.3 105 124 73 (1) 6.4 190.5 8 1-1/8 1 165
3 240 127 38.1 102 127 88.9 (1) 9.5 190.5 8 1 7/8 150
4 290 157.2 44.5 114 159 114.3 (1) 12.7 235 8 1-1/4 1-1/8 180
6 380 215.9 55.6 140 235 168.3 (1) 12.7 317.5 12 1-1/4 1-1/8 195
8 470 269.9 63.5 162 298 219.1 (1) 12.7 393.7 12 1-1/2 1-3/8 230
10 545 323.8 69.9 184 368 273 (1) 12.7 469.9 16 1-1/2 1-3/8 240
12 610 381 79.4 200 419 323.8 (1) 12.7 533.4 20 1-1/2 1-3/8 260
14 640 412.8 85.8 213 451 355.6 (1) 12.7 558.8 20 1-5/8 1-1/2 280
16 705 469.9 88.9 216 508 406.4 (1) 12.7 616 20 1-3/4 1-5/8 290
18 785 533.4 101.6 229 565 457.2 (1) 12.7 685.8 20 2 1-7/8 330
20 855 584.2 108 248 622 508 (1) 12.7 749.3 20 2-1/8 2 355
24 1040 692.2 139.7 292 749 609.6 (1) 12.7 901.7 20 2-5/8 2-1/2 445

Note - (1) : Bore diameter of Orfice Flange (B) shall be specified by Purchaser.