Type and Construction
The composite blind flanges are in accordance with manufacturer’s specification. The range of sizes covered is ½ in./16 mm to 36 in./914 mm Class 150. Drilling and outside diameter dimensions of flange sizes ½ in./16 mm-24 in./610 mm are in accordance with ANSI B16.5 and BS 1560, whereas the larger sizes, 28 in./711 mm -36 in./914 mm are in accordance with MSS SP-44. The blind flanges are suitable for use both 16 and 20 bar systems.

The composite blind flanges are manufactured from forged carbon steel in accordance with ASTM A105 cladded with copper nickel disk. In contrast to raised face blind flanges in accordance to ANSI B16.5, the supplied composite flanges are considered as flat face, since the diameter of the copper nickel disk d1 is equivalent to the flange diameter d4 weld neck stub end in accordance with EEMUA 234, Section 1A. By these means, uniform contact over the weld neck stub end faces is ensured. The recommended bolting is in accordance with ASTM A193-B7. Unless otherwise specified the flanges are protected by hot dipped galvanising. Additional organic coatings such as polyamide epoxy are available on request. Solid blind flanges are available on request.

Tolerances
Tolerances are equivalent to the dimensions for weld neck backing flanges based on EEMUA – 234, Section 1B, Table 1.5.2.

Nom.

Spec.

Flange

 

Diameter of Bolt Holes 

Flange

Diameter of

No. Of

Approx.

Size

Size

Diameter

K

d2 

Thickness

Disk

Bolt

Total Weight

in

mm

D mm

mm

in

mm

b min mm

d1 mm

Holes

(kg)

½

16

89

60.3

5/8

15.9

14

40

4

0.82

¾

25

98

69.8

5/8

15.9

14

50

4

1.04

1

30

108

79.4

5/8

15.9

14

50

4

1.31

38

117

88.9

5/8

15.9

14

70

4

1.58

44.5

127

98.4

5/8

15.9

14

80

4

1.90

2

57

152

120.6

3/4

19.0

18

99

4

3.01

76.1

178

139.7

3/4

19.0

18

120

4

4.68

3

88.9

190

152.4

3/4

19.0

19

130

4

5.70

4

108

229

190.5

3/4

19.0

24

158

8

8.67

6

159

279

241.3

7/8

22.2

27

212

8

15.46

8

219.1

343

298.4

7/8

22.2

31

270

8

24.90

10

267

406

362.0

1

25.4

38

320

12

41.23

12

323.9

483

431.8

1

25.4

41

370

12

70.55

14

368

533

476.2

1 1/8

28.6

45

430

12

93.16

16

419

597

539.8

1 1/8

28.6

51

482

16

123.99

18

457.2

635

577.8

1 1/4

31.8

52

530

16

147.55

20

508

698

635.0

1 1/4

31.8

58

585

20

191.00

24

610

813

749.3

1 3/8

34.9

71

685

20

285.74

28

711

927

864.0

1 3/8

34.9

81

800

28

434.66

32

813

1060

978.0

1 5/8

41.1

95

905

28

665.63

36

914

1168

1086.0

1 5/8

41.1

105

1000

32

886.43