Flange and Bolt Dimensions - 150 lb to 2500 lb - ASME/ANSI B16.5
 

Diameters and bolt circles for standard ASME B16.5 flanges - 1/4 to 24 inches - 150 psi to 2500 psi

 

Nominal Pipe Size
NPS
(inches)

150 psi

Diameter of
Flange
(inches)

No.
of
Bolts

Diameter of
Bolts
(inches)

Bolt
Circle
(inches)

1/4

3-3/8

4

1/2

2-1/4

1/2

3-1/2

4

1/2

2-3/8

3/4

3-7/8

4

1/2

2-3/4

1

4-1/4

4

1/2

3-1/8

1-1/4

4-5/8

4

1/2

3-1/2

1-1/2

5

4

1/2

3-7/8

2

6

4

5/8

4-3/4

2-1/2

7

4

5/8

5-1/2

3

7-1/2

4

5/8

6

3-1/2

8-1/2

8

5/8

7

4

9

8

5/8

7-1/2

5

10

8

3/4

8-1/2

6

11

8

3/4

9-1/2

8

13-1/2

8

3/4

11-3/4

10

16

12

7/8

14-1/4

12

19

12

7/8

17

14

21

12

1

18-3/4

16

23-1/2

16

1

21-1/4

18

25

16

1-1/8

22-3/4

20

27-1/2

20

1-1/8

25

24

32

20

1-1/4

29-1/2

 

Nominal Pipe Size
NPS
(inches)

300 psi

Diameter of
Flange
(inches)

No.
of
Bolts

Diameter of
Bolts
(inches)

Bolt
Circle
(inches)

1/4

3-3/8

4

1/2

2-1/4

1/2

3-3/4

4

1/2

2-5/8

3/4

4-5/8

4

5/8

3-1/4

1

4-7/8

4

5/8

3-1/2

1-1/4

5-1/4

4

5/8

3-7/8

1-1/2

6-1/8

4

3/4

4-1/2

2

6-1/2

8

5/8

5

2-1/2

7-1/2

8

3/4

5-7/8

3

8-1/4

8

3/4

6-5/8

3-1/2

9

8

3/4

7-1/4

4

10

8

3/4

7-7/8

5

11

8

3/4

9-1/4

6

12-1/2

12

3/4

10-5/8

8

15

12

7/8

13

10

17-1/2

16

1

15-1/4

12

20-1/2

16

1-1/8

17-3/4

14

23

20

1-1/8

20-1/4

16

25-1/2

20

1-1/4

22-1/2

18

28

24

1-1/4

24-3/4

20

30-1/2

24

1-1/4

27

24

36

24

1-1/2

32

 

Nominal Pipe Size
NPS
(inches)

400 psi

Diameter of
Flange
(inches)

No.
of
Bolts

Diameter of
Bolts
(inches)

Bolt
Circle
(inches)

1/4

3-3/8

4

1/2

2-1/4

1/2

3-3/4

4

1/2

2-5/8

3/4

4-5/8

4

5/8

3-1/4

1

4-7/8

4

5/8

3-1/2

1-1/4

5-1/4

4

5/8

3-7/8

1-1/2

6-1/8

4

3/4

4-1/2

2

6-1/2

8

5/8

5

2-1/2

7-1/2

8

3/4

5-7/8

3

8-1/4

8

3/4

6-5/8

3-1/2

9

8

7/8

7-1/4

4

10

8

7/8

7-7/8

5

11

8

7/8

9-1/4

6

12-1/2

12

7/8

10-5/8

8

15

12

1

13

10

17-1/2

16

1-1/8

15-1/4

12

20-1/2

16

1-1/4

17-3/4

14

23

20

1-1/4

20-1/4

16

25-1/2

20

1-3/8

22-1/2

18

28

24

1-3/8

24-3/4

20

30-1/2

24

1-1/2

27

24

36

24

1-3/4

32

 

Nominal Pipe Size
NPS
(inches)

600 psi

Diameter of
Flange
(inches)

No.
of
Bolts

Diameter of
Bolts
(inches)

Bolt
Circle
(inches)

1/4

3-3/8

4

1/2

2-1/4

1/2

3-3/4

4

1/2

2-5/8

3/4

4-5/8

4

5/8

3-1/4

1

4-7/8

4

5/8

3-1/2

1-1/4

5-1/4

4

5/8

3-7/8

1-1/2

6-1/8

4

3/4

4-1/2

2

6-1/2

8

5/8

5

2-1/2

7-1/2

8

3/4

5-7/8

3

8-1/4

8

3/4

6-5/8

3-1/2

9

8

7/8

7-1/4

4

10-3/4

8

7/8

8-1/2

5

13

8

1

10-1/2

6

14

12

1

11-1/2

8

16-1/2

12

1-1/8

13-3/4

10

20

16

1-1/4

17

12

22

20

1-1/4

19-1/4

14

23-3/4

20

1-3/8

20-3/4

16

27

20

1-1/2

23-3/4

18

29-1/4

20

1-5/8

25-3/4

20

32

24

1-5/8

28-1/2

24

37

24

1-7/8

33

 

Nominal Pipe Size
NPS
(inches)

900 psi

Diameter of
Flange
(inches)

No.
of
Bolts

Diameter of
Bolts
(inches)

Bolt
Circle
(inches)

1/2

4-3/4

4

3/4

3-1/4

3/4

5-1/8

4

3/4

3-1/2

1

5-7/8

4

7/8

4

1-1/4

6-1/4

4

7/8

4-3/8

1-1/2

7

4

1

4-7/8

2

8-1/2

8

7/8

6-1/2

2-1/2

9-5/8

8

1

7-1/2

3

9-1/2

8

7/8

7-1/2

4

11-1/2

8

1-1/8

9-1/4

5

13-3/4

8

1-1/4

11

6

15

12

1-1/8

12-1/2

8

18-1/2

12

1-3/8

15-1/2

10

21-1/2

16

1-3/8

18-1/2

12

24

20

1-3/8

21

14

25-1/4

20

1-1/2

22

16

27-3/4

20

1-5/8

24-1/2

18

31

20

1-7/8

27

20

33-3/4

20

2

29-1/2

24

41

20

2-1/2

35-1/2

 

Nominal Pipe Size
NPS
(inches)

1500 psi

Diameter of
Flange
(inches)

No.
of
Bolts

Diameter of
Bolts
(inches)

Bolt
Circle
(inches)

1/2

4-3/4

4

3/4

3-1/4

3/4

5-1/8

4

3/4

3-1/2

1

5-7/8

4

7/8

4

1-1/4

6-1/4

4

7/8

4-3/8

1-1/2

7

4

1

4-7/8

2

8-1/2

8

7/8

6-1/2

2-1/2

9-5/8

8

1

7-1/2

3

10-1/2

8

1-1/8

8

4

12-1/4

8

1-1/4

9-1/2

5

14-3/4

8

1-1/2

11-1/2

6

15-1/2

12

1-3/8

12-1/2

8

19

12

1-5/8

15-1/2

10

23

12

1-7/8

19

12

26-1/2

16

2

22-1/2

14

29-1/2

16

2-1/4

25

16

32-1/2

16

2-1/2

27-3/4

18

36

16

2-3/4

30-1/2

20

38-3/4

16

3

32-3/4

24

46

16

3-1/2

39

 

Nominal Pipe Size
NPS
(inches)

2500 psi

Diameter of
Flange
(inches)

No.
of
Bolts

Diameter of
Bolts
(inches)

Bolt
Circle
(inches)

1/2

5-1/4

4

3/4

3-1/2

3/4

5-1/2

4

3/4

3-3/4

1

6-1/4

4

7/8

4-1/4

1-1/4

7-1/4

4

1

5-1/8

1-1/2

8

4

1-1/8

5-3/4

2

9-1/4

8

1

6-3/4

2-1/2

10-1/2

8

1-1/8

7-3/4

3

12

8

1-1/4

9

4

14

8

1-1/2

10-3/4

5

16-1/2

8

1-3/4

12-3/4

6

19

8

2

14-1/2

8

21-3/4

12

2

17-1/4

10

26-1/2

12

2-1/2

21-1/4

12

30

12

2-3/4

24-3/8

 

 

What is DN?

DN stands for 'Diameter Nominale'.

Put simply, it is a rough translation of mm from imperial sizes, assuming that an inch is 25mm.

We refer to a 12" flange as DN300, when in fact it is 304mm.

½"

DN15

 

6"

DN150

¾"

DN20

 

8"

DN200

1"

DN25

 

10"

DN250

1¼"

DN32

 

12"

DN300

1½"

DN40

 

14"

DN350

2"

DN50

 

15"

DN375

2½"

DN65

 

16"

DN400

3"

DN80

 

18"

DN450

4"

DN100

 

20"

DN500

5"

DN125

 

24"

DN600

What is the PCD?

The PCD of a flange is one of the critical dimensions.

PCD (Pitch Circle Diameter) is the diameter of a circle that goes through each of the bolt holes.

 There are several standards for flanges, and we deal with four of them;

 

British Standard - BS10

Table D

Table E

Table F

Table G

Table H

Table J

Table K

 

Table E is the most popular for applications with water.

All dimensions are specified in inches.

 

Australian Standard - AS2129

Table C

Table D

Table E

Table F

Table G

Table H

Table J

 

These flanges are equivalent to the BS10 flanges, except that all dimensions are specified in mm.

In some sizes, bolt holes are slightly larger to give better clearance.

 

American National Standards Institute (ANSI)

ANSI 125

ANSI 150

ANSI 300

ANSI 600

ANSI 900

ANSI 1500

 

Higher numbers denote higher pressures.

Sometimes people use the word 'Class' instead of ANSI. e.g. an ANSI 150 flange might be called a 'Class 150'

All dimensions are specified in inches.

 

British Standard - BS4504

BS4504-6

BS4504-10

BS4504-16

BS4504-25

BS4504-40

BS4504-64

BS4504-100

PN6

PN10

PN16

PN25

PN40

PN64

PN100

Engineers use the prefix PN (Pressure Nominale). e.g. a BA4504-16 flange will commonly be referred to as a PN16

Generally, a PN16 flange is designed to withstand pressures up to 16 bar.

All dimensions are specified in mm.

 

Connexion Developments Ltd, Unit 3, Rainbow Court, Great Western Business Park, Yate, BS37 5NG
Tel no 01454 334 990 FAX 01454 326 390 Email: sales@solenoidvalvesuk.com Reg. in England No. 3502257