Dimensions of Class 2500 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
Dia

No.
of
Bolt
Holes
Dia
of
Bolt
Holes
Dia
of
Bolts
Stud
Bolt
Length
1 160 50.8 38.1 92 57 33.5 (1) 6.4 108 4 1 7/8 150
1-1/2 205 73 44.5 111 79 48.3 (1) 6.4 146 4 1-1/4 1-1/8 180
2 235 92.1 50.8 127 95 60.3 (1) 6.4 171.4 8 1-1/8 1 185
2-1/2 265 104.8 57.2 143 114 73 (1) 6.4 196.8 8 1-1/4 1-1/8 205
3 305 127 66.7 168 133 88.9 (1) 9.5 228.6 8 1-3/8 1-1/4 230
4 355 157.2 76.2 190 165 114.3 (1) 12.7 273 8 1-5/8 1-1/2 260
6 485 215.9 108 273 235 168.3 (1) 12.7 368.3 8 2-1/8 2 350
8 550 269.9 127 318 305 219.1 (1) 12.7 438.2 12 2-1/8 2 385
10 675 323.8 165.1 419 375 273 (1) 12.7 539.8 12 2-5/8 2-1/2 490
12 760 381 184.2 464 441 323.8 (1) 12.7 619.1 12 2-7/8 2-3/4 540

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