DN

D

C1

C2

H1

H2

H3

R

A

N1

N2

B1

d1

f1

DN

K

L

No

Size

10

90

14

14

20

35

6

3

17,2

28

30

18

40

2

mm

mm

mm

-

mm

15

95

14

14

20

35

6

3

21,3

32

35

22

45

2

10

60

14

4

M12

20

105

14

14

24

38

6

4

26,9

39

45

27,5

58

2

15

65

14

4

M12

25

115

16

16

24

38

6

4

33,7

46

52

34,5

68

2

20

75

14

4

M12

32

140

18

16

26

40

6

5

42,4

56

60

43,5

78

2

25

85

14

4

M12

40

150

18

16

26

42

7

5

48,3

64

70

49,5

88

3

32

100

18

4

M16

50

165

20

18

28

45

8

5

60,3

74

84

61,5

102

3

40

110

18

4

M16

65

185

20

18

32

45

10

6

76,1

92

104

77,5

122

3

50

125

18

4

M16

80

200

20

20

34

50

10

6

88,9

110

118

90,5

138

3

65

145

18

8

M16

100

220

22

20

40

52

12

6

114,3

130

140

116

162

3

80

160

18

8

M16

125

250

22

22

44

55

12

6

139,7

158

168

141,5

188

3

100

180

18

8

M16

150

285

24

22

44

55

12

8

168,3

184

195

170,5

212

3

125

210

18

8

M16

200

340

26

24

44

62

16

8

219,1

234

246

221,5

268

3

150

240

22

8

M20

250

405

29

26

46

70

16

10

273

288

298

276,5

320

3

200

295

22

12

M20

300

460

32

28

46

78

16

10

323,9

342

350

327,5

378

4

250

355

26

12

M24

350

520

35

30

57

82

16

10

355,6

390

400

359

438

4

300

410

26

12

M24

400

580

38

32

63

85

16

10

406,4

444

456

411,0

490

4

350

470

26

16

M24

450

640

42

34

68

87

16

12

457,0

490

502

462,0

550

4

400

525

30

16

M27

500

715

46

34

73

90

16

12

508,0

546

559

513,5

610

4

450

585

30

20

M27

600

840

52

36

83

95

18

12

610,0

650

658

616,5

725

5

500

650

33

20

M30

700

910

60

36

83

100

18

12

711,0

750

760

-

795

5

600

770

36

20

M33

800

1025

68

38

90

105

20

12

813,0

848

864

-

900

5

700

840

36

24

M33

900

1125

76

40

94

110

20

12

914,0

948

968

-

1000

5

800

950

39

24

M36

1000

1255

84

42

100

120

22

12

1016,0

1056

1072

-

1115

5

900

1050

39

28

M36

1200

1485

98

48

-

130

30

12

1220,0

1260

-

-

1330

5

1000

1170

42

28

M39

1400

1685

-

52

-

145

30

12

1420,0

1465

-

-

1530

5

1200

1390

48

32

M45

1600

1930

-

58

-

160

35

12

1620,0

1668

-

-

1750

5

1400

1590

48

36

M45

DN

D

C1

C2

H1

H2

H3

R

A

N1

N2

B1

d1

f1

1600

1820

56

40

M52

DN

K

L

No

Size

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.

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.