WELDING NECK FLANGES ASME B16.5 Class 900

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
Number of
Bolt Holes
Diameter
of
Bolt
Holes
Diameter
of
Bolts
Diameter
of
Bolt
Circle
Approx.
Weight

Pounds
Kg

O C R X A Y
½
¾
1
1 ¼
1 ½ Size ½ thru 2 ½ areidentical toClass 1500
2
2 ½
3 in. 9.50 1.50 5.00 5.00 3.50 4.00 8 1.00  7/8 7.50 31
3 ½ mm 241.30 38.10 127.00 127.00 88.90 101.60 25.40 22.20 190.50 14
4 in. 11.50 1.75 6.19 6.25 4.50 4.50 8 1.25 1 1/8 9.25 53
mm 292.10 44.50 157.20 158.80 114.30 114.30 31.80 28.60 235.00 24
5 in. 13.75 2.00 7.31 7.50 5.56 5.00 8 1.38 1 ¼ 11.00 86
mm 349.30 50.80 185.70 190.50 141.20 127.00 35.10 31.80 279.40 39
6 in. 15.00 2.19 8.50 9.25 6.63 5.50 12 1.25 1 1/8 12.50 110
mm 381.00 55.60 215.90 235.00 168.40 139.70 31.80 28.60 317.50 50
8 in. 18.50 2.50 10.62 11.75 8.63 6.38 12 1.50 1 3/8 15.50 175
mm 469.90 63.50 269.70 298.50 219.20 162.10 38.10 34.90 393.70 79
10 in. 21.50 2.75 12.75 14.50 10.75 7.25 16 1.50 1 3/8 18.50 260
mm 546.10 69.90 323.90 368.30 273.10 184.20 38.10 34.90 469.90 118
12 in. 24.00 3.12 15.00 16.50 12 75 7.88 20 1 50 1 3/8 21.00 325
mm 609.60 79.20 381.00 419.10 323.90 200.20 38.10 34.90 533.40 147
14 in. 25.25 3.38 16.25 17.75 14.00 8.38 20 1.62 1 ½ 22.00 400
mm 641.40 85.90 412.80 450.90 355.60 212.90 41.10 38.10 558.80 181
16 in. 27.75 3 50 18.50 20.00 16.00 8.50 20 1.75 1 5/8 24.25 495
mm 704.90 88.90 469.90 508.00 406 4 215.90 44.50 41.30 616.00 225
18 in. 31.00 4.00 21.00 22.25 18.00 9.00 20 2.00 1 7/8 27.00 680
mm 787.40 101.60 533.40 565.20 457.20 228.60 50.80 47.60 685.80 308
20 in. 33.75 4.25 23.00 24.50 20.00 9.75 20 2.12 2.00 29.50 830
mm 857.30 108.00 584.20 622.30 508.00 247.70 53.80 50.80 749.30 376
24 in. 41.00 5.50 27.25 29.50 24.00 11.50 20 2.62 2 ½ 35.50 1500
mm 1041.40 139.70 692.20 749.30 609.60 292.10 66.50 63.50 901.70 680