Flanges – Dimensions ANSI/ASME B16.5
ASME/ANSI B16.5 provides
flange dimensions for pipes ranging 1/2″ to 24″ – in classes ranging 150 to 2500.
Nominal Pipe Size NPS (inches) |
Class 150 | ||||
---|---|---|---|---|---|
Diameter of Flange (inches) |
No. of Bolts |
Diameter of Bolts (inches) |
Diameter of Bolt Holes (inches) |
Bolt Circle (inches) |
|
1/4 | 3-3/8 | 4 | 1/2 | 0.62 | 2-1/4 |
1/2 | 3-1/2 | 4 | 1/2 | 0.62 | 2-3/8 |
3/4 | 3-7/8 | 4 | 1/2 | 0.62 | 2-3/4 |
1 | 4-1/4 | 4 | 1/2 | 0.62 | 3-1/8 |
1-1/4 | 4-5/8 | 4 | 1/2 | 0.62 | 3-1/2 |
1-1/2 | 5 | 4 | 1/2 | 0.62 | 3-7/8 |
2 | 6 | 4 | 5/8 | 0.75 | 4-3/4 |
2-1/2 | 7 | 4 | 5/8 | 0.75 | 5-1/2 |
3 | 7-1/2 | 4 | 5/8 | 0.75 | 6 |
3-1/2 | 8-1/2 | 8 | 5/8 | 0.75 | 7 |
4 | 9 | 8 | 5/8 | 0.75 | 7-1/2 |
5 | 10 | 8 | 3/4 | 0.88 | 8-1/2 |
6 | 11 | 8 | 3/4 | 0.88 | 9-1/2 |
8 | 13-1/2 | 8 | 3/4 | 0.88 | 11-3/4 |
10 | 16 | 12 | 7/8 | 1 | 14-1/4 |
12 | 19 | 12 | 7/8 | 1 | 17 |
14 | 21 | 12 | 1 | 1.12 | 18-3/4 |
16 | 23-1/2 | 16 | 1 | 1.12 | 21-1/4 |
18 | 25 | 16 | 1-1/8 | 1.25 | 22-3/4 |
20 | 27-1/2 | 20 | 1-1/8 | 1.25 | 25 |
24 | 32 | 20 | 1-1/4 | 1.38 | 29-1/2 |
Nominal Pipe Size NPS (inches) |
Class 300 | ||||
---|---|---|---|---|---|
Diameter of Flange (inches) |
No. of Bolts |
Diameter of Bolts (inches) |
Diameter of Bolt Holes (inches) |
Bolt Circle (inches) |
|
1/4 | 3-3/8 | 4 | 1/2 | 0.62 | 2-1/4 |
1/2 | 3-3/4 | 4 | 1/2 | 0.62 | 2-5/8 |
3/4 | 4-5/8 | 4 | 5/8 | 0.75 | 3-1/4 |
1 | 4-7/8 | 4 | 5/8 | 0.75 | 3-1/2 |
1-1/4 | 5-1/4 | 4 | 5/8 | 0.75 | 3-7/8 |
1-1/2 | 6-1/8 | 4 | 3/4 | 0.88 | 4-1/2 |
2 | 6-1/2 | 8 | 5/8 | 0.75 | 5 |
2-1/2 | 7-1/2 | 8 | 3/4 | 0.88 | 5-7/8 |
3 | 8-1/4 | 8 | 3/4 | 0.88 | 6-5/8 |
3-1/2 | 9 | 8 | 3/4 | 0.88 | 7-1/4 |
4 | 10 | 8 | 3/4 | 0.88 | 7-7/8 |
5 | 11 | 8 | 3/4 | 0.88 | 9-1/4 |
6 | 12-1/2 | 12 | 3/4 | 0.88 | 10-5/8 |
8 | 15 | 12 | 7/8 | 1 | 13 |
10 | 17-1/2 | 16 | 1 | 1.12 | 15-1/4 |
12 | 20-1/2 | 16 | 1-1/8 | 1.25 | 17-3/4 |
14 | 23 | 20 | 1-1/8 | 1.25 | 20-1/4 |
16 | 25-1/2 | 20 | 1-1/4 | 1.38 | 22-1/2 |
18 | 28 | 24 | 1-1/4 | 1.38 | 24-3/4 |
20 | 30-1/2 | 24 | 1-1/4 | 1.38 | 27 |
24 | 36 | 24 | 1-1/2 | 1.62 | 32 |
Nominal Pipe Size NPS (inches) |
Class 400 | ||||
---|---|---|---|---|---|
Diameter of Flange (inches) |
No. of Bolts |
Diameter of Bolts (inches) |
Diameter of Bolt Holes (inches) |
Bolt Circle (inches) |
|
1/4 | 3-3/8 | 4 | 1/2 | 0.62 | 2-1/4 |
1/2 | 3-3/4 | 4 | 1/2 | 0.62 | 2-5/8 |
3/4 | 4-5/8 | 4 | 5/8 | 0.75 | 3-1/4 |
1 | 4-7/8 | 4 | 5/8 | 0.75 | 3-1/2 |
1-1/4 | 5-1/4 | 4 | 5/8 | 0.75 | 3-7/8 |
1-1/2 | 6-1/8 | 4 | 3/4 | 0.88 | 4-1/2 |
2 | 6-1/2 | 8 | 5/8 | 0.75 | 5 |
2-1/2 | 7-1/2 | 8 | 3/4 | 0.88 | 5-7/8 |
3 | 8-1/4 | 8 | 3/4 | 0.88 | 6-5/8 |
3-1/2 | 9 | 8 | 7/8 | 1 | 7-1/4 |
4 | 10 | 8 | 7/8 | 1 | 7-7/8 |
5 | 11 | 8 | 7/8 | 1 | 9-1/4 |
6 | 12-1/2 | 12 | 7/8 | 1 | 10-5/8 |
8 | 15 | 12 | 1 | 1.12 | 13 |
10 | 17-1/2 | 16 | 1-1/8 | 1.25 | 15-1/4 |
12 | 20-1/2 | 16 | 1-1/4 | 1.38 | 17-3/4 |
14 | 23 | 20 | 1-1/4 | 1.38 | 20-1/4 |
16 | 25-1/2 | 20 | 1-3/8 | 1.5 | 22-1/2 |
18 | 28 | 24 | 1-3/8 | 1.5 | 24-3/4 |
20 | 30-1/2 | 24 | 1-1/2 | 1.62 | 27 |
24 | 36 | 24 | 1-3/4 | 1.88 | 32 |
Nominal Pipe Size NPS (inches) |
Class 600 | ||||
---|---|---|---|---|---|
Diameter of Flange (inches) |
No. of Bolts |
Diameter of Bolts (inches) |
Diameter of Bolt Holes (inches) |
Bolt Circle (inches) |
|
1/4 | 3-3/8 | 4 | 1/2 | 0.62 | 2-1/4 |
1/2 | 3-3/4 | 4 | 1/2 | 0.62 | 2-5/8 |
3/4 | 4-5/8 | 4 | 5/8 | 0.75 | 3-1/4 |
1 | 4-7/8 | 4 | 5/8 | 0.75 | 3-1/2 |
1-1/4 | 5-1/4 | 4 | 5/8 | 0.75 | 3-7/8 |
1-1/2 | 6-1/8 | 4 | 3/4 | 0.88 | 4-1/2 |
2 | 6-1/2 | 8 | 5/8 | 0.75 | 5 |
2-1/2 | 7-1/2 | 8 | 3/4 | 0.88 | 5-7/8 |
3 | 8-1/4 | 8 | 3/4 | 0.88 | 6-5/8 |
3-1/2 | 9 | 8 | 7/8 | 1 | 7-1/4 |
4 | 10-3/4 | 8 | 7/8 | 1 | 8-1/2 |
5 | 13 | 8 | 1 | 1.12 | 10-1/2 |
6 | 14 | 12 | 1 | 1.12 | 11-1/2 |
8 | 16-1/2 | 12 | 1-1/8 | 1.25 | 13-3/4 |
10 | 20 | 16 | 1-1/4 | 1.38 | 17 |
12 | 22 | 20 | 1-1/4 | 1.38 | 19-1/4 |
14 | 23-3/4 | 20 | 1-3/8 | 1.5 | 20-3/4 |
16 | 27 | 20 | 1-1/2 | 1.62 | 23-3/4 |
18 | 29-1/4 | 20 | 1-5/8 | 1.75 | 25-3/4 |
20 | 32 | 24 | 1-5/8 | 1.75 | 28-1/2 |
24 | 37 | 24 | 1-7/8 | 2 | 33 |
Nominal Pipe Size NPS (inches) |
Class 900 | ||||
---|---|---|---|---|---|
Diameter of Flange (inches) |
No. of Bolts |
Diameter of Bolts (inches) |
Diameter of Bolt Holes (inches) |
Bolt Circle (inches) |
|
1/2 | 4-3/4 | 4 | 3/4 | 0.88 | 3-1/4 |
3/4 | 5-1/8 | 4 | 3/4 | 0.88 | 3-1/2 |
1 | 5-7/8 | 4 | 7/8 | 1 | 4 |
1-1/4 | 6-1/4 | 4 | 7/8 | 1 | 4-3/8 |
1-1/2 | 7 | 4 | 1 | 1.12 | 4-7/8 |
2 | 8-1/2 | 8 | 7/8 | 1 | 6-1/2 |
2-1/2 | 9-5/8 | 8 | 1 | 1.12 | 7-1/2 |
3 | 9-1/2 | 8 | 7/8 | 1 | 7-1/2 |
4 | 11-1/2 | 8 | 1-1/8 | 1.25 | 9-1/4 |
5 | 13-3/4 | 8 | 1-1/4 | 1.38 | 11 |
6 | 15 | 12 | 1-1/8 | 1.25 | 12-1/2 |
8 | 18-1/2 | 12 | 1-3/8 | 1.5 | 15-1/2 |
10 | 21-1/2 | 16 | 1-3/8 | 1.5 | 18-1/2 |
12 | 24 | 20 | 1-3/8 | 1.5 | 21 |
14 | 25-1/4 | 20 | 1-1/2 | 1.62 | 22 |
16 | 27-3/4 | 20 | 1-5/8 | 1.75 | 24-1/2 |
18 | 31 | 20 | 1-7/8 | 2 | 27 |
20 | 33-3/4 | 20 | 2 | 2.12 | 29-1/2 |
24 | 41 | 20 | 2-1/2 | 2.62 | 35-1/2 |
Nominal Pipe Size NPS (inches) |
Class 1500 | ||||
---|---|---|---|---|---|
Diameter of Flange (inches) |
No. of Bolts |
Diameter of Bolts (inches) |
Diameter of Bolt Holes (inches) |
Bolt Circle (inches) |
|
1/2 | 4-3/4 | 4 | 3/4 | 0.88 | 3-1/4 |
3/4 | 5-1/8 | 4 | 3/4 | 0.88 | 3-1/2 |
1 | 5-7/8 | 4 | 7/8 | 1 | 4 |
1-1/4 | 6-1/4 | 4 | 7/8 | 1 | 4-3/8 |
1-1/2 | 7 | 4 | 1 | 1.12 | 4-7/8 |
2 | 8-1/2 | 8 | 7/8 | 1 | 6-1/2 |
2-1/2 | 9-5/8 | 8 | 1 | 1.12 | 7-1/2 |
3 | 10-1/2 | 8 | 1-1/8 | 1.25 | 8 |
4 | 12-1/4 | 8 | 1-1/4 | 1.38 | 9-1/2 |
5 | 14-3/4 | 8 | 1-1/2 | 1.62 | 11-1/2 |
6 | 15-1/2 | 12 | 1-3/8 | 1.5 | 12-1/2 |
8 | 19 | 12 | 1-5/8 | 1.75 | 15-1/2 |
10 | 23 | 12 | 1-7/8 | 2 | 19 |
12 | 26-1/2 | 16 | 2 | 2.12 | 22-1/2 |
14 | 29-1/2 | 16 | 2-1/4 | 2.38 | 25 |
16 | 32-1/2 | 16 | 2-1/2 | 2.62 | 27-3/4 |
18 | 36 | 16 | 2-3/4 | 2.88 | 30-1/2 |
20 | 38-3/4 | 16 | 3 | 3.12 | 32-3/4 |
24 | 46 | 16 | 3-1/2 | 3.62 | 39 |
Nominal Pipe Size NPS (inches) |
Class 2500 | ||||
---|---|---|---|---|---|
Diameter of Flange (inches) |
No. of Bolts |
Diameter of Bolts (inches) |
Diameter of Bolt Holes (inches) |
Bolt Circle (inches) |
|
1/2 | 5-1/4 | 4 | 3/4 | 0.88 | 3-1/2 |
3/4 | 5-1/2 | 4 | 3/4 | 0.88 | 3-3/4 |
1 | 6-1/4 | 4 | 7/8 | 1 | 4-1/4 |
1-1/4 | 7-1/4 | 4 | 1 | 1.12 | 5-1/8 |
1-1/2 | 8 | 4 | 1-1/8 | 1.25 | 5-3/4 |
2 | 9-1/4 | 8 | 1 | 1.12 | 6-3/4 |
2-1/2 | 10-1/2 | 8 | 1-1/8 | 1.25 | 7-3/4 |
3 | 12 | 8 | 1-1/4 | 1.38 | 9 |
4 | 14 | 8 | 1-1/2 | 1.62 | 10-3/4 |
5 | 16-1/2 | 8 | 1-3/4 | 1.88 | 12-3/4 |
6 | 19 | 8 | 2 | 2.12 | 14-1/2 |
8 | 21-3/4 | 12 | 2 | 2.12 | 17-1/4 |
10 | 26-1/2 | 12 | 2-1/2 | 2.62 | 21-1/4 |
12 | 30 | 12 | 2-3/4 | 2.88 | 24-3/8 |