WELDING NECK ORIFICE FLANGES B16.36 Class 400

Nominal
Size
NPS
Outside
Diameter
of
Flange
Thickness
of
Flange
Diameter Of Raised
Face
Diameter Of Hub At Base Diameter Of Hub At Point of Welding Length
thru
Hub
Diameter Of Pressure Connection Number of
Bolt Holes
Diameter
of
Bolt
Holes
Diameter
of
Bolts
Diameter
of
Bolt
Circle
Groove Number Pitch
Diameter
Groove
Depth
Groove
Width
Radius
At Bottom
Spec.
Oval  R.H.
O C R X A Y TT P E F r max. W
1 in.
mm
1 ½ in.
mm
2 in. Sizes 1” thru 3” are identical to class 600
mm
2 ½ in.
mm
3 in.
mm
4 in. 10 1.5 6.19 5.75 4.5 3.5 ½ 8 1  7/8 7.88 R37 5.875 0.312 0.469 0.03 1.06
mm 254 38.1 157.2 146.1 114.3 88.9 12.7 25.4 22.2 200.2 149.225 7.925 11.913 0.8 26.9
6 in. 12.5 1.62 8.5 8.12 6.63 4.06 ½ 12 1  7/8 10.62 R45 8.312 0.312 0.469 0.03 1.06
mm 317.5 41.1 215.9 206.2 168.4 103.1 12.7 25.4 22.2 269.7 211.125 7.925 11.913 0.8 26.9
8 in. 15 1.88 10.62 10.25 8.63 4.62 ½ 12 1.12 1 13 R49 10.625 0.312 0.469 0.03 1.06
mm 381 47.8 269.7 260.4 219.2 117.3 12.7 28.4 25.4 330.2 269.875 7.925 11.913 0.8 26.9
10 in. 17.5 2.12 12.75 12.62 10.75 4.88 ½ 16 1.25 1 1/8 15.25 R53 12.75 0.312 0.469 0.03 1.06
mm 444.5 53.8 323.9 320.5 273.1 124 12.7 31.8 28.6 387.4 323.85 7.925 11.913 0.8 26.9
12 in. 20.5 2.25 15 14.75 12.75 5.38 ½ 16 1.38 1 ¼ 17.75 R57 15 0.312 0.469 0.03 1.06
mm 520.7 57.2 381 374.7 323.9 136.7 12.7 35.1 31.8 450.9 381 7.925 11.913 0.8 26.9
14 in. 23 2.39 16.25 16.75 14 5.88 ½ 20 1.38 1 ¼ 20.25 R61 16.5 0.312 0.469 0.03 1.06
mm 584.2 60.7 412.8 425.5 355.6 149.4 12.7 35.1 31.8 514.4 419.1 7.925 11.913 0.8 26.9
16 in. 25.5 2.5 18.5 19 16 6 ½ 20 1.5 1 3/8 22.5 R65 18.5 0.312 0.469 0.03 1.19
mm 647.7 63.5 469.9 482.6 406.4 152.4 12.7 38.1 34.9 571.5 469.9 7.925 11.913 0.8 30.2
18 in. 28 2.62 21 21 18 6.5 ½ 24 1.5 1 3/8 24.75 R69 21 0.312 0.469 0.03 1.19
mm 711.2 66.5 533.4 533.4 457.2 165.1 12.7 38.1 34.9 628.7 533.4 7.925 11.913 0.8 30.2
20 in. 30.5 2.75 23 23.12 20 6.62 ½ 24 1.62 1 ½ 27 R73 23 0.375 0.531 0.06 1.25
mm 774.7 69.9 584.2 587.2 508 168.1 12.7 41.1 38.1 685.8 584.2 9.525 13.487 1.5 31.8
24 in. 36 3 27.25 27.62 24 6.88 ½ 24 1.88 1 ¾ 32 R77 27.25 0.938 0.656 0.06 1.44
mm 914.4 76.2 692.2 701.5 609.6 174.8 12.7 47.7 44.5 812.8 692.15 23.82 16.66 1.52 36.57