ASTM Class 150 Welding Neck Flanges

Nominal Pipe SizeOutside Diameter (O)Thickness (T)Raised Face Diameter (R)Length Thru Hub (Y)Point Of WeldHub Diameter (X)Bore (B)Approximate Weight (lbs)Bolt Circle (C)Number of HolesDiameter of Holes
1/2 3.50 0.44 1.38 1.88 0.84 1.19 0.62 2 2.38 4 0.63
3/4 3.88 0.50 1.69 2.06 1.05 1.50 0.82 2 2.75 4 0.63
1 4.25 0.56 2.00 2.19 1.32 1.94 1.05 3 3.13 4 0.63
1 1/4 4.63 0.63 2.50 2.25 1.66 2.31 1.38 3 3.50 4 0.63
1 1/2 5.00 0.69 2.88 2.44 1.90 2.56 1.61 4 3.88 4 0.63
2 6.00 0.75 3.63 2.50 2.38 3.06 2.07 6 4.75 4 0.75
2 1/2 7.00 0.88 4.13 2.75 2.88 3.56 2.47 8 5.50 4 0.75
3 7.50 0.94 5.00 2.75 3.50 4.25 3.07 10 6.00 4 0.75
3 1/2 8.50 0.94 5.50 2.81 4.00 4.81 3.55 12 7.00 8 0.75
4 9.00 0.94 6.19 3.00 4.50 5.31 4.03 15 7.50 8 0.75
5 10.00 0.94 7.31 3.50 5.56 6.44 5.05 19 8.50 8 0.88
6 11.00 1.00 8.50 3.50 6.63 7.56 6.07 24 9.50 8 0.88
8 13.50 1.13 10.63 4.00 8.63 9.69 7.98 39 11.75 8 0.88
10 16.00 1.19 12.75 4.00 10.75 12.00 10.02 52 14.25 12 1.00
12 19.00 1.25 15.00 4.50 12.75 14.38 12.00 80 17.00 12 1.00
14 21.00 1.38 16.25 5.00 14.00 15.75 13.25 110 18.75 12 1.13
16 23.50 1.44 18.50 5.00 16.00 18.00 15.25 140 21.25 16 1.13
18 25.00 1.56 21.00 5.50 18.00 19.88 17.25 150 22.75 16 1.25
20 27.50 1.69 23.00 5.69 20.00 22.00 19.25 180 25.00 20 1.25
22 29.50 1.81 25.25 5.88 22.00 24.25 21.25 225 27.25 20 1.38
24 32.00 1.88 27.25 6.00 24.00 26.13 23.25 260 29.50 20 1.38