Spectacle Blind Flanges

  • Size: 1/2″ thru 24″ or custom size.
  • Material: Nickel Alloy,Hastelloy Alloy,Monel Alloy,Inconel Allo, Anti-Corrosion Resistant Alloy, Super-Alloy, Duplex Steel, Stainless steel, Titanium Alloy, Copper Alloy, Carbon Steel, Aluminium Steel, ect.
  • Standard: A WWA C207, ASME B16.5, DIN, BS, JIS, EN1092-1, ASME B16.47 and GOST/ГОСТ Standard, etc..
  • Approved by CE, RoHs, SGS, BV
  • Large stock with different sizes

Spectacle Blind Flanges Solutions

In an industry that thrives on efficiency and safety, spectacle blind flanges solutions are worth their weight in gold. They allow for easy isolation of pipeline sections during maintenance, reducing the risk of spills and accidents while keeping downtime to a minimum.

Table of Contents

Understanding your choice of spectacle blind flanges options

Spectacle blind flanges are indispensable components in various industries, offering safety and versatility for diverse applications. Understanding the different options, materials, standards, and maintenance requirements of figure-8 blind flanges can help you select the right product for your piping system and ensure its safe and efficient operation. Spectacle blind flanges are essential in piping systems, providing a safe and efficient means of isolating sections for maintenance, inspection, or repair. These specialized flanges are designed with two interconnected sections: a solid plate to block the flow of fluids and a spacer to allow fluid passage when needed.

20230322020144 76896 - Spectacle Blind Flanges

What is a spectacle blind flange?

A spectacle blind flange, also known as a figure-of-8 blind, “spectacle flange,” is made by a steel spade and spacer, united by a welded handle: one is actually a ring (i.e., a disc with a hole of the same diameter as the pipe) and the other is a solid disc. The figure 8 blind blocks or isolates a portion of the piping system during maintenance operations and provides a firm seal when closed.
Under normal conditions, the spectacle blind is installed in the open position and does not interrupt the flow of fluid conveyed by the pipeline.
To block the pipeline and interrupt the flow, field personnel unscrew the flange bolts and rotate the eight-hole blind to the closed position.
If the spectacle blind is in the open or closed position, this is easy to understand because one of the two discs is always on the outside of the pipe (so when the ring is visible, the pipe is closed; when the solid disc is visible, the line is open). For shovels and ring gaskets, the holes in the hanger will inform the crew.

Advantages of Using Spectacle Blind Flanges

Spectacle Blind Flanges offer numerous benefits to industries requiring efficient and reliable isolation of piping sections. Some of these advantages include the following:

  1. Safety: Spectacle blind flanges provide a safe method of isolating pipeline sections, preventing the accidental release of hazardous substances during maintenance or inspection.
  2. Versatility: These flanges can be used in various applications, including high-pressure, high-temperature, and corrosive environments, making them suitable for multiple industries.
  3. Ease of Use: The design of spectacle blind flanges allows for easy installation and removal, reducing downtime and labor costs associated with maintenance and repair.
  4. Leak Prevention: High-quality spectacle blind flanges are manufactured with precision, ensuring proper alignment and sealing, thereby reducing the risk of leakage and improving overall system performance.
  5. Cost-effective: By using spectacle blind flanges, industries can eliminate the need for additional valves, reducing overall costs and simplifying the piping system.

Types of spectacle blind flanges

There are several types of Spectacle Blind Flanges available in the market, each designed for a specific application. Some common types include:
Raised Face Spectacle Blind Flanges
Raised face spectacle blind flanges are the most common type and feature a raised surface around the bore to ensure proper sealing. They are suitable for applications with high pressure and temperature requirements.
Flat Face Spectacle Blind Flanges
Flat face spectacle blind flanges have a flat sealing surface and are typically used in low-pressure applications or when mating with other flat-faced flanges.
Ring Type Joint Spectacle Blind Flanges
Ring type joint spectacle blind flanges feature a grooved sealing surface and are used in high-pressure applications where a metal-to-metal seal is required.

How to measure a spectacle blind flange?

20230322035748 13791 - Spectacle Blind Flanges

To measure a spectacle blind flange accurately, you should follow these steps:
Measuring Flange Diameter

  • Lay the spectacle blind flange on a flat surface.
  • Use a measuring tape or a caliper to measure the outer diameter (OD) of the flange from one edge to the other, passing through the center.

Measuring Flange Thickness

  • Place the measuring tool, such as a caliper or a ruler, on the edge of the flange.
  • Measure the thickness of the flange, ensuring that you’re measuring the thickest part.

Measuring Bolt Hole Diameter

  • Position the measuring tool over a bolt hole.
  • Measure the diameter of the hole from one side to the other.

Measuring Bolt Circle Diameter

  • Locate two opposing bolt holes on the flange.
  • Use a measuring tape or a caliper to measure the distance between the center of one bolt hole to the center of the opposite bolt hole, ensuring that the measurement passes through the center of the flange. This is the bolt circle diameter (BCD).

Standard for spectacle blind flanges

Several international standards and specifications govern the design, dimensions, and manufacturing of spectacle blind flanges. Some of the most widely recognized standards include:

  • ASME B16.48: This American standard covers the pressure-temperature ratings, materials, dimensions, tolerances, and marking requirements for spectacle blind flanges.
  • MSS SP-44: A standard developed by the Manufacturers Standardization Society, MSS SP-44 covers the dimensions, materials, and manufacturing requirements for spectacle blind flanges in the petroleum and natural gas industries.
  • EN 1092-1: This European standard specifies the dimensions, materials, and design requirements for spectacle blind flanges used in piping systems.

Materials of spectacle blind flanges

Depending on the specific application requirements, spectacle blind flanges are made from a variety of metal materials, including:

Titanium spectacle blind flange ASTM B381 / ASME SB381, Titanium Gr. 1, Titanium Gr. 2, Titanium Gr. 4, Titanium Gr. 5, Titanium Gr. 7, ASTM R50250/GR.1| R50400/GR.2 | R50550/GR.3 | R50700/GR.4 | GR.6 |R52400/GR.7 | R53400/GR.12 | R56320/GR.9 |R56400/GR.5
Copper spectacle blind flange T1, T2, C10100, C10200, C10300, C10400, C10500, C10700, C10800, C10910,C10920, TP1, TP2, C10930, C11000, C11300, C11400, C11500, C11600, C12000,C12200, C12300, TU1, TU2, C12500, C14200, C14420, C14500, C14510, C14520, C14530, C17200, C19200, C21000, C23000, C26000, C27000, C27400, C28000, C33000, C33200, C37000, C44300, C44400, C44500, C60800, C63020, C68700, C70400, C70600, C70620, C71000, C71500, C71520, C71640, etc
Copper Nickel spectacle blind flange ASTM / ASME SB 61 / 62 / 151 / 152, Copper Nickel 90/10 (C70600 ), Cupro Nickel 70/30 (C71500), UNS C71640
Carbon Steel spectacle blind flange ASTM/ASME A/SA105 A/SA105N & A/SA216-WCB, DIN 1.0402, DIN 1.0460, DIN 1.0619, Die Steel, ASTM A105 / ASME SA105, A105N, ASTM A350 LF2 / ASME SA350, High Yield CS ASTM A694 / A694 (F52 F56 F60 F65 F70 F80)
Stainless Steel spectacle blind flange ASTM/ASME A/SA182 F304, F304L, F316, F316L, ASTM/ASME A/SA351 CF8, CF3, CF8M, CF3M, DIN 1.4301, DIN 1.4306, DIN 1.4401, DIN 1.4404, DIN 1.4308, DIN 1.4408, DIN 1.4306, DIN 1.4409
Alloy Steel spectacle blind flange ASTM A182 / ASME SA182 F5, F9, F11, F12, F22, F91
Hastelloy spectacle blind flange ASTM B564 / ASME SB564, Hastelloy C276 (UNS N10276), C22 (UNS N06022), C4, C2000, B2, B3, X
Brass spectacle blind flange 3602 / 2604 / H59 / H62 / etc.
Inconel spectacle blind flange ASTM B564 / ASME SB564, Inconel 600, 601, 625, 718, 783, 690, x750
Monel spectacle blind flange ASTM B564 / ASME SB564, Monel 400 (UNS No. N04400), Monel 500 (UNS No. N05500)
Duplex spectacle blind flange S31803 / S32205 A182 Gr F51 / F52 / F53 / F54 / F55 / F57 / F59 / F60 / F61
Super Duplex spectacle blind flange S32750 / S32760 A182 Gr F51 / F52 / F53 / F54 / F55 / F57 / F59 / F60 / F61
Alloy 20 spectacle blind flange ASTM B462 / ASME SB462, Carpenter 20 Alloy, Alloy 20Cb-3
Aluminium spectacle blind flange 5052 /6061/ 6063 / 2017 / 7075 / etc.
Nickel spectacle blind flange ASTM B564 / ASME SB564, Nickel 200, Nickel 201, Nickel 205, Nickel 205LC
Nimonic spectacle blind flange Nimonic 75, Nimonic 80A, Nimonic 90
Other spectacle blind flange material Tin bronze, Alumunum bronze, Lead bronze
Incoloy spectacle blind flange ASTM B564 / ASME SB564, Incoloy 800, 800H, 800HT (UNS N08800), 825 (UNS N08825), 925
254 Smo spectacle blind flange ASTM A182 / ASME SA182, SMO 254/6Mo, UNS S31254, DIN 1.4547

Selecting the Right spectacle blind flange Material

  • Material selection is crucial when choosing spectacle blind flanges for your piping system. Factors to consider include corrosion resistance, temperature, and pressure requirements. Common materials used for spectacle blind flanges include:
  • Carbon Steel: Offers excellent strength and durability, making it suitable for high-pressure applications.
  • Stainless Steel: Provides outstanding corrosion resistance, making it ideal for use in harsh environments or applications where chemical compatibility is essential.
  • Alloy Steel: Delivers enhanced resistance to heat and corrosion, making it suitable for high-temperature and high-pressure environments.
  • Nickel Alloys: Offer superior corrosion and heat resistance, as well as excellent mechanical properties, making them suitable for use in demanding applications such as aerospace, power generation, and petrochemical industries.

Dimensions of spectacle blind flanges

Spectacle blind flanges are available in various sizes and dimensions, ranging from 1/2″ to 60″ in diameter, with pressure ratings from 150 to 2500 Class. The size and dimensions of a spectacle blind flange depend on the pipe size, pressure, and temperature requirements.

Dimensions of ASME B16.48 Figure-8 Blanks/Spectacle Blinds RF/FF

20230322040928 11919 - Spectacle Blind Flanges 20230322040938 67092 - Spectacle Blind Flanges
ASME B16.48 Figure-8 Blanks/Spectacle Blinds FF ASME B16.48 Figure-8 Blanks/Spectacle Blinds RF
Technical drawing for the figure-8 blank (spectacle blind flange) in accordance with ASME B16.48, with flat face. O: outside diameter; A: center distance; T: thickness of blank; W: web width; B: inside diameter of the open end; t: thickness of tie bar. Technical drawing for the figure-8 blank (spectacle blind flange) in accordance with ASME B16.48, with raised face. The RF dimensions shall be furnished in accordance with ASME B16.5. The height of the raised face shall be in addition to the thickness T. For Class 150 & 300, the height of RF shall be 2 mm; for Class 600, 900, 1500 & 2500, the height of RF shall be 7 mm.

Dimensions for ASME B16.48 Class 150 figure-8 blanks (spectacle blind flanges) with FF or RF.

NPS

O

A

T

W

B

1/2

45

60

3.0

38

16

3/4

54

70

3.0

38

21

1

64

80

3.0

38

27

1-1/4

73

90

6.4

38

42

1-1/2

83

100

6.4

38

48

2

102

120

6.4

51

61

2-1/2

107

140

6.4

51

73

3

133

150

6.4

64

89

3-1/2

159

175

9.7

64

102

4

172

190

9.7

64

114

5

194

215

9.7

76

141

6

219

240

12.7

76

168

8

276

300

12.7

76

219

10

337

360

15.7

102

273

12

406

430

19.1

102

324

14

448

475

19.1

108

356

16

511

540

22.4

108

406

18

546

580

25.4

114

457

20

603

635

28.4

121

508

24

714

750

31.8

140

610

Dimensions for ASME B16.48 Class 300 figure-8 blanks (spectacle blind flanges) with FF or RF.

NPS

O

A

T

W

B

1/2

51

65

6.4

38

16

3/4

64

80

6.4

38

21

1

70

90

6.4

38

27

1-1/4

79

100

6.4

38

42

1-1/2

92

115

6.4

38

48

2

108

125

9.7

51

61

2-1/2

127

150

9.7

51

73

3

146

170

9.7

64

89

3-1/2

162

185

12.7

64

102

4

178

200

12.7

64

114

5

213

235

15.7

76

141

6

248

270

15.7

76

168

8

305

330

22.4

76

219

10

359

385

25.4

102

273

12

419

450

28.4

102

324

14

483

515

31.8

108

356

16

536

570

38.1

108

406

18

594

630

41.1

114

457

20

651

685

44.5

121

508

24

772

810

50.8

140

610

Dimensions for ASME B16.48 Class 600 figure-8 blanks (spectacle blind flanges) with FF or RF.

NPS

O

A

T

W

B

1/2

51

65

6.4

38

16

3/4

64

80

6.4

38

21

1

70

90

6.4

57

27

1-1/4

79

100

9.7

57

37

1-1/2

92

115

9.7

67

43

2

108

125

9.7

57

55

2-1/2

127

150

12.7

67

67

3

146

170

12.7

67

83

3-1/2

159

185

15.7

76

96

4

191

215

15.7

76

108

5

238

265

19.1

86

135

6

264

290

22.4

86

162

8

318

350

28.4

95

212

10

397

430

35.1

105

265

12

454

490

41.1

105

315

14

489

525

44.5

114

346

16

562

605

50.8

124

397

18

610

655

53.8

133

448

20

679

725

63.5

133

497

24

787

840

73.2

152

597

Dimensions for ASME B16.48 Class 900 figure-8 blanks (spectacle blind flanges) with FF or RF.

NPS

O

A

T

W

B

1/2

60

80

6.4

38

16

3/4

67

90

6.4

41

21

1

76

100

6.4

57

27

1-1/4

86

110

9.7

57

37

1-1/2

95

125

9.7

67

43

2

140

165

12.7

57

55

2-1/2

162

190

12.7

67

67

3

165

190

15.7

67

83

4

203

235

19.1

76

108

5

244

280

22.4

86

135

6

286

320

25.4

86

162

8

356

395

35.1

95

212

10

432

470

41.1

105

265

12

495

535

47.8

105

315

14

518

560

53.8

114

346

16

572

615

60.5

124

397

18

635

685

66.5

133

448

20

696

750

73.2

133

497

24

835

900

88.9

152

597

Dimensions for ASME B16.48 Class 1500 figure-8 blanks (spectacle blind flanges) with FF or RF.

NPS

O

A

T

W

B

1/2

61

80

6.4

38

16

3/4

67

90

9.7

41

21

1

76

100

9.7

64

27

1-1/4

86

110

9.7

64

35

1-1/2

95

125

12.7

70

41

2

140

165

12.7

70

53

2-1/2

162

190

15.7

76

63

3

172

205

19.1

76

78

4

206

240

22.4

89

102

5

251

290

28.4

89

128

6

279

320

35.1

89

154

8

349

395

41.1

102

203

10

432

480

50.8

114

255

12

518

570

60.5

114

303

14

575

635

66.5

127

333

16

638

705

76.2

133

381

18

702

775

85.9

146

429

20

752

830

95.3

152

478

24

899

990

111.3

178

575

Dimensions for ASME B16.48 Class 2500 figure-8 blanks (spectacle blind flanges) with FF or RF.

NPS

O

A

T

W

B

1/2

67

90

9.7

38

16

3/4

73

95

9.7

41

21

1

83

110

9.7

64

27

1-1/4

102

130

12.7

64

35

1-1/2

114

145

15.7

70

41

2

143

170

15.7

70

53

2-1/2

165

195

19.1

76

63

3

194

230

22.4

76

78

4

232

275

28.4

89

102

5

276

325

35.1

89

128

6

314

370

41.1

89

154

8

384

440

53.8

102

198

10

473

540

66.5

114

248

12

546

620

79.2

114

289

Weights for spectacle blinds in sizes NPS 1/2″ through 24″ of Class 150, 300 & 600.

NPS

150#

300#

600#

1/2

0.12

0.25

0.38

3/4

0.17

0.38

0.57

1

0.23

0.46

0.73

1-1/4

0.49

0.56

1.24

1-1/2

0.63

0.76

1.65

2

0.96

1.46

2.33

2-1/2

1.07

1.98

3.61

3

1.59

2.61

4.87

3-1/2

3.00

3.93

6.46

4

3.52

4.73

9.00

5

4.34

7.93

15.34

6

6.66

10.56

21.06

8

10.19

21.16

35.75

10

17.59

31.63

64.41

12

30.31

47.11

94.88

14

36.80

71.30

116.37

16

55.11

102.25

171.78

18

68.18

133.67

210.36

20

90.98

170.85

299.91

24

139.19

269.41

447.64

Weights for spectacle blinds in sizes NPS 1/2″ through 24″ of Class 900, 1500 & 2500.

NPS

900#

1500#

2500#

1/2

0.46

0.46

0.72

3/4

0.61

0.79

0.89

1

0.80

1.05

1.19

1-1/4

1.37

1.40

2.14

1-1/2

1.73

2.08

3.17

2

3.98

4.04

4.90

2-1/2

5.21

6.21

7.50

3

6.68

8.47

11.81

4

11.45

13.58

20.45

5

18.15

23.62

34.01

6

27.04

34.45

49.98

8

53.48

60.13

94.12

10

88.31

108.77

171.27

12

130.89

182.62

268.26

14

156.56

245.28

16

208.72

339.62

18

278.80

457.52

20

361.74

569.25

24

619.04

936.93

Dimensions of ASME B16.48 Figure-8 Blanks/Spectacle Blinds Female RTJ

20230322063429 86988 - Spectacle Blind Flanges
ASME B16.48 Figure-8 Blank/Spectacle Blind Female RTJ
Technical drawing for the female ring-joint facing (F/RTJ) figure-8 blank (spectacle blind flange) made in accordance with ASME B16.48. A: centerline distance; O: outside diameter of blank flange; B: inside diameter of the open end; T: blank thickness; W: web width; t: thickness of the tie bar.

Dimensions for ASME B16.48 Class 150 figure-8 blanks/spectacle blind flanges with female ring-joint facing (F/RTJ).

NPS

O

A

T

W

B

1

64

80

19.1

51

34

1-1/4

73

90

19.1

51

42

1-1/2

83

100

19.1

57

48

2

102

120

19.1

57

61

2-1/2

121

140

22.4

57

73

3

133

150

22.4

57

89

3-1/2

154

175

22.4

64

102

4

172

190

22.4

64

114

5

194

215

25.4

70

141

6

219

240

25.4

83

168

8

273

300

28.4

95

219

10

330

360

31.8

102

273

12

406

430

35.1

121

324

14

426

475

35.1

127

356

16

483

540

38.1

127

406

18

546

580

41.1

127

457

20

597

635

41.1

127

508

24

711

750

47.8

152

610

Dimensions for ASME B16.48 Class 300 figure-8 blanks/spectacle blind flanges with female ring-joint facing (F/RTJ).

NPS

O

A

T

W

B

1/2

51

65

15.7

38

21

3/4

64

80

19.1

45

27

1

70

90

19.1

51

34

1-1/4

79

100

22.4

51

42

1-1/2

90

115

22.4

57

48

2

108

125

25.4

57

61

2-1/2

127

150

28.4

57

73

3

146

170

28.4

57

89

3-1/2

159

185

28.4

64

102

4

175

200

31.8

64

114

5

210

235

35.1

70

141

6

241

270

35.1

83

168

8

302

330

41.1

95

219

10

356

385

44.5

102

273

12

413

450

50.8

121

324

14

457

515

53.8

127

356

16

508

570

57.2

127

406

18

575

630

60.5

127

457

20

635

685

69.9

127

508

24

749

810

79.2

152

610

Dimensions for ASME B16.48 Class 600 figure-8 blanks/spectacle blind flanges with female ring-joint facing (F/RTJ).

NPS

O

A

T

W

B

1/2

51

65

19.1

38

21

3/4

64

80

22.4

45

27

1

70

90

22.4

51

34

1-1/4

79

100

22.4

51

42

1-1/2

90

115

22.4

57

48

2

108

125

28.4

57

61

2-1/2

127

150

31.8

57

73

3

146

170

31.8

57

89

3-1/2

159

185

35.1

64

102

4

175

215

35.1

64

114

5

210

265

38.1

70

141

6

241

290

44.5

83

168

8

302

350

50.8

95

219

10

356

430

57.2

102

273

12

413

490

63.5

121

324

14

457

525

66.5

127

356

16

508

605

73.2

127

406

18

575

655

79.2

127

457

20

635

725

88.9

127

508

24

749

840

104.6

152

610

Dimensions for ASME B16.48 Class 900 figure-8 blanks/spectacle blind flanges with female ring-joint facing (F/RTJ).

NPS

O

A

T

W

B

1/2

61

80

22.4

38

21

3/4

67

90

22.4

45

27

1

71

100

22.4

51

34

1-1/4

81

110

25.4

51

42

1-1/2

92

125

25.4

64

48

2

124

165

31.8

51

61

2-1/2

137

190

35.1

67

73

3

155

190

35.1

67

89

4

181

235

41.1

73

114

5

216

280

44.5

73

141

6

241

315

47.8

73

168

8

308

395

57.2

80

219

10

362

470

63.5

121

273

12

419

535

73.2

121

324

14

467

560

82.6

121

356

16

524

615

91.9

127

406

18

594

685

101.6

133

457

20

648

750

111.3

127

508

24

772

900

133.4

140

610

Dimensions for ASME B16.48 Class 1500 figure-8 blanks/spectacle blind flanges with female ring-joint facing (F/RTJ).

NPS

O

A

T

W

B

1/2

61

80

22.4

38

21

3/4

67

90

25.4

45

27

1

71

100

25.4

54

34

1-1/4

81

110

25.4

54

42

1-1/2

92

125

28.4

57

48

2

124

165

35.1

54

61

2-1/2

137

190

38.1

57

73

3

168

205

44.5

73

89

4

194

240

47.8

76

114

5

229

290

53.8

76

141

6

248

315

60.5

79

168

8

318

395

73.2

86

219

10

371

480

82.5

133

273

12

438

570

101.6

133

324

14

489

635

111.3

140

356

16

546

705

124.0

146

406

18

613

775

133.0

152

457

20

673

830

142.7

165

508

24

794

990

168.1

178

610

Dimensions for ASME B16.48 Class 2500 figure-8 blanks/spectacle blind flanges with female ring-joint facing (F/RTJ).

NPS

O

A

T

W

B

1/2

65

90

25.4

38

21

3/4

73

95

28.4

45

27

1

83

110

28.4

54

34

1-1/4

102

130

35.1

54

42

1-1/2

114

145

38.1

61

48

2

133

170

41.1

57

61

2-1/2

149

195

47.8

61

73

3

168

230

50.8

76

89

4

203

270

63.5

83

114

5

241

325

73.2

89

141

6

279

370

82.6

95

168

8

340

440

98.6

95

219

10

425

540

117.3

91

273

12

495

620

133.4

152

324

Weights for spectacle blinds in sizes NPS 1/2″ through 24″ of Class 150, 300 & 600.

NPS

150#

300#

600#

1/2

0.11

0.24

0.36

3/4

0.16

0.37

0.55

1

0.22

0.44

0.70

1-1/4

0.47

0.54

1.19

1-1/2

0.61

0.73

1.59

2

0.92

1.40

2.24

2-1/2

1.02

1.90

3.47

3

1.53

2.51

4.67

3-1/2

2.88

3.77

6.20

4

3.38

4.54

8.64

5

4.17

7.61

14.72

6

6.40

10.14

20.22

8

9.79

20.31

34.32

10

16.89

30.37

61.83

12

29.10

45.22

91.09

14

35.32

68.44

111.71

16

52.91

98.16

164.91

18

65.45

128.33

201.95

20

87.34

164.02

287.92

24

133.62

258.63

429.73

Weights for spectacle blinds in sizes NPS 1/2″ through 24″ of Class 900, 1500 & 2500.

NPS

900#

1500#

2500#

1/2

0.44

0.45

0.69

3/4

0.58

0.76

0.85

1

0.77

1.00

1.14

1-1/4

1.31

1.34

2.06

1-1/2

1.66

2.00

3.04

2

3.82

3.88

4.70

2-1/2

5.00

5.96

7.20

3

6.42

8.13

11.34

4

10.99

13.04

19.63

5

17.42

22.68

32.65

6

25.95

33.07

47.98

8

51.34

57.73

90.35

10

84.77

104.42

164.42

12

125.66

175.32

257.53

14

150.30

235.47

16

200.37

326.04

18

367.65

439.22

20

347.27

546.48

24

594.27

899.45

Dimensions of ASME B16.48 Figure-8 Blanks/Spectacle Blinds Male RTJ

20230322065007 69383 - Spectacle Blind Flanges
ASME B16.48 Figure-8 Blanks/Spectacle Blinds Male RTJ
Technical drawing for the male ring-joint facing figure-8 blank (spectacle blind flange) made in accordance with ASME B16.48. B: inside diameter of the open end; t: thickness of tie bar; A: centerline distance; W: web width; T: blank thickness.

Dimensions for ASME B16.48 Class 150 figure-8 blanks/spectacle blind flanges with male ring-joint facing (M/RTJ).

NPS

A

T

W

B

1

80

6.4

51

34

1-1/4

90

6.4

51

42

1-1/2

100

6.4

57

48

2

120

6.4

57

61

2-1/2

140

9.7

57

73

3

150

9.7

57

89

3-1/2

175

9.7

64

102

4

190

9.7

64

114

5

215

12.7

70

141

6

240

12.7

83

168

8

300

15.7

95

219

10

362

19.1

102

273

12

432

22.4

121

324

14

476

22.4

127

356

16

540

25.4

127

406

18

578

28.4

127

457

20

635

28.4

127

508

24

749

35.1

152

610

Dimensions for ASME B16.48 Class 300 figure-8 blanks/spectacle blind flanges with male ring-joint facing (M/RTJ).

NPS

A

T

W

B

1/2

65

6.4

38

21

3/4

80

9.7

45

27

1

90

9.7

51

34

1-1/4

100

9.7

51

42

1-1/2

115

9.7

57

48

2

125

12.7

57

61

2-1/2

150

15.7

57

73

3

170

15.7

57

89

3-1/2

180

15.7

64

102

4

200

15.7

64

114

5

235

19.1

76

141

6

270

22.4

83

168

8

330

25.4

95

219

10

390

28.4

102

273

12

450

35.1

121

324

14

515

38.1

127

356

16

570

41.1

127

406

18

630

44.5

127

457

20

685

50.8

127

508

24

810

57.2

152

610

Dimensions for ASME B16.48 Class 600 figure-8 blanks/spectacle blind flanges with male ring-joint facing (M/RTJ).

NPS

A

T

W

B

1/2

65

6.4

38

21

3/4

80

9.7

45

27

1

90

9.7

51

34

1-1/4

100

9.7

57

42

1-1/2

115

9.7

57

48

2

125

12.7

51

61

2-1/2

150

15.7

57

73

3

170

15.7

67

89

3-1/2

180

19.1

67

102

4

215

19.1

73

114

5

265

22.4

73

141

6

290

28.4

73

168

8

350

35.1

83

219

10

430

41.1

121

273

12

490

47.8

121

324

14

525

50.8

121

356

16

605

57.2

127

406

18

650

63.5

133

457

20

720

69.9

127

508

24

840

82.6

152

610

Dimensions for ASME B16.48 Class 900 figure-8 blanks/spectacle blind flanges with male ring-joint facing (M/RTJ).

NPS

A

T

W

B

1/2

80

9.7

38

21

3/4

90

9.7

45

27

1

100

9.7

51

34

1-1/4

110

12.7

54

42

1-1/2

125

12.7

54

48

2

165

15.7

51

61

2-1/2

190

19.1

54

73

3

190

19.1

67

89

4

235

25.4

73

114

5

280

28.4

73

141

6

315

31.8

73

168

8

395

41.1

79

219

10

470

47.8

121

273

12

535

57.2

121

324

14

560

60.5

121

356

16

615

69.9

127

406

18

685

76.2

133

457

20

750

85.9

127

508

24

900

98.6

152

610

Dimensions for ASME B16.48 Class 1500 figure-8 blanks/spectacle blind flanges with male ring-joint facing (M/RTJ).

NPS

A

T

W

B

1/2

83

9.7

38

21

3/4

89

9.7

45

27

1

102

12.7

54

34

1-1/4

111

12.7

54

42

1-1/2

124

15.7

57

48

2

165

19.1

54

61

2-1/2

191

22.4

57

73

3

203

28.4

73

89

4

241

31.8

76

114

5

292

38.1

76

141

6

318

41.1

79

168

8

394

50.8

86

219

10

483

63.5

133

273

12

572

73.2

133

324

14

635

79.2

140

356

16

705

88.9

146

406

18

775

98.6

152

457

20

832

108.0

165

508

24

991

127.0

178

610

Dimensions for ASME B16.48 Class 2500 figure-8 blanks/spectacle blind flanges with male ring-joint facing (M/RTJ).

NPS

A

T

W

B

1/2

90

12.7

41

21

3/4

95

15.7

48

27

1

110

15.7

54

34

1-1/4

130

19.1

54

42

1-1/2

145

22.4

61

48

2

170

25.4

57

61

2-1/2

195

28.4

61

73

3

230

31.8

76

89

4

270

38.1

83

114

5

325

47.8

89

141

6

370

57.2

95

168

8

440

69.9

95

219

10

540

82.6

95

273

12

620

98.6

152

324

Weights for spectacle blinds in sizes NPS 1/2″ through 24″ of Class 150, 300 & 600.

NPS

150#

300#

600#

1/2

0.11

0.23

0.34

3/4

0.15

0.34

0.51

1

0.21

0.42

0.66

1-1/4

0.44

0.51

1.11

1-1/2

0.57

0.68

1.49

2

0.86

1.32

2.10

2-1/2

0.96

1.78

3.25

3

1.43

2.35

4.38

3-1/2

2.70

3.54

5.81

4

3.17

4.26

8.10

5

3.91

7.14

13.80

6

6.00

9.51

18.95

8

9.17

19.04

32.17

10

15.83

28.47

57.97

12

27.28

42.40

85.39

14

33.12

64.17

104.73

16

49.60

92.03

154.61

18

61.36

120.31

189.33

20

81.88

153.77

269.92

24

125.27

242.47

402.87

Weights for spectacle blinds in sizes NPS 1/2″ through 24″ of Class 900, 1500 & 2500.

NPS

900#

1500#

2500#

1/2

0.41

0.42

0.64

3/4

0.55

0.71

0.80

1

0.72

0.94

1.07

1-1/4

1.23

1.26

1.93

1-1/2

1.55

1.87

2.85

2

3.59

3.63

4.41

2-1/2

4.69

5.59

6.75

3

6.02

7.62

10.63

4

10.31

12.22

18.40

5

16.34

21.26

30.61

6

24.33

31.01

44.98

8

48.13

54.12

84.71

10

79.48

97.90

154.15

12

117.80

164.36

241.44

14

140.91

220.76

16

187.84

305.66

18

250.92

411.77

20

325.57

512.32

24

557.13

843.24

Difference between the blind flange and spectacle blind flange

A blind flange and a spectacle blind flange are integral components of piping and process systems. They serve distinct purposes and possess different features. This technical document aims to elucidate the primary differences between the two in terms of design, function, and applications.

Design:

Blind Flange: A blind flange is a solid, flat, circular plate devoid of any opening in its center. It is designed to be bolted to a pipe, valve, or another flange, effectively sealing the end of a pipe or system. The outer edge of the blind flange is equipped with bolt holes that align with those on the mating flange, facilitating easy installation and removal.

Spectacle Blind Flange: A spectacle blind flange, also known as a figure-8 blind, comprises two interconnected discs – one solid and one with an opening matching the pipe’s inner diameter. The reliable and holed discs resemble an “8” shape, hence the name. This unique design allows easy switching between the open and closed positions by rotating the spectacle blind flange.

Function:

Blind Flange: The primary function of a blind flange is to provide a secure, leak-proof closure at the end of a piping system, isolating it from the rest of the process. This is particularly useful during maintenance, testing, or decommissioning activities, ensuring a safe working environment for personnel and equipment.

Spectacle Blind Flange: The spectacle blind flange serves a dual purpose – isolation and flow control. In the closed position (solid disc covering the pipe), it isolates a section of the piping system for maintenance or repairs, similar to a blind flange. The open position (holed disc aligned with the pipe) allows for the unobstructed flow of fluid or gas through the pipeline, thus enabling regular operation.

Applications:

Blind Flange: Blind flanges are widely used across various industries, such as oil and gas, petrochemical, chemical, power generation, and water treatment plants, to isolate or terminate pipelines, pressure vessels, or equipment during maintenance, inspection, or repairs.

Spectacle Blind Flange: Spectacle blind flanges are commonly employed in industries with stringent safety and operational requirements, such as oil refineries, chemical plants, and offshore platforms. They offer quick and easy flow control without disassembling the piping system, reducing downtime and increasing overall efficiency.

The primary differences between a blind flange and a spectacle blind flange lie in their design, function, and applications. While a blind flange is a solid, flat plate used for isolating sections of a piping system, a spectacle blind flange comprises interconnected solid and holed discs, allowing for both isolation and flow control. Depending on the application’s specific requirements, these distinct features dictate their respective usage in different industrial settings.

How to use a spectacle blind flange?

20230322081409 21639 - Spectacle Blind Flanges

The Spectacle Blind is usually used on the oil line with two different functions:

  • If the spade is put in between the flanges, it stops the fluid’s passage;
  • The fluid path is allowed if the spacer is placed between the flanges.

The Spectacle Blind is inserted between two flanges: to guarantee a perfect watertight, two gaskets usually are mounted, one on each side of the spectacle blind.
Spectacle blind flanges are a type of flow control device used in piping systems to isolate sections or regulate fluid flow. They consist of two circular plates, one with a hole (spacer) and the other without (spade), connected by a handle or web. The spacer and spade can be rotated to allow or block the flow through the pipe.

Manufacturing Process of spectacle blind flanges

Spectacle blind flanges are crucial components in piping systems, utilized to provide flexibility in managing flow and isolating specific sections when needed. These flanges are designed with a unique figure-eight shape, consisting of one solid and one open section. This configuration allows for easy flow manipulation through the piping system, depending on the operational requirements.

Section 1: Raw Materials and Spectacle Blind Flange Composition

The manufacturing process of spectacle blind flanges begins with selecting high-quality raw materials. Commonly used materials include carbon steel, stainless steel, alloy steel, and various other metals, depending on the specific requirements and application. The material selection is crucial to ensure the flanges’ durability, resistance to corrosion, and ability to withstand the operating conditions they will be subjected to.

Section 2: Cutting and Shaping the Spectacle Blind Flange

Once the appropriate material is selected, the manufacturing process moves to the cutting and shaping stage. The raw material is precisely cut to the desired figure-eight shape using advanced machinery, such as CNC, plasma, and water jet cutting machines.

The cutting process must be accurate, ensuring that the dimensions of the solid and open sections of the spectacle blind flange meet the required specifications. Additionally, the edges of the flange must be smooth and burr-free to ensure proper sealing when installed in the piping system.

Section 3: Drilling and Machining the Bolt Holes

After cutting the flange to its unique shape, the next step involves drilling and machining the bolt holes. These holes allow the spectacle blind flange to be securely fastened to the adjacent flanges in the piping system, ensuring a leak-free connection. The drilling process must be precise, guaranteeing that the bolt holes are evenly spaced and aligned.

Section 4: Heat Treatment and Surface Finishing

To enhance the mechanical properties of the spectacle blind flange, heat treatment processes, such as normalizing, annealing, or quenching and tempering, may be employed. These treatments improve the flange’s strength, ductility, and resistance to wear and corrosion.

Once the heat treatment is complete, the spectacle blind flange undergoes surface finishing. This step involves sandblasting, pickling, or electro-polishing, which remove any surface imperfections and enhance the flange’s appearance and corrosion resistance.

Section 5: Quality Assurance and Testing

Quality assurance and testing are vital stages in the manufacturing process of spectacle blind flanges. Various tests ensure that the flanges meet the required standards and specifications. These tests may include the following:

  • Dimensional inspection: Verifying that the flange’s dimensions, such as thickness, diameter, and bolt-hole spacing, are within the specified tolerances.

  • Visual inspection: Checking for surface defects, such as cracks, pits, or other imperfections.

  • Material analysis: Confirm that the flange’s composition matches the required material specifications.

  • Mechanical and physical testing: Evaluating the flange’s mechanical properties, such as tensile strength, yield strength, and elongation, to ensure it meets the required standards.

Section 6: Marking and Packaging

Once the spectacle blind flange passes all quality assurance tests, it is marked with essential information, such as material grade, size, pressure rating, and the manufacturer’s name or logo. This marking ensures traceability and confirms that the flange meets the required standards.

Packing of spectacle blind flanges

How to package spectacle blind flanges? To pack the spectacle blind flange, follow these steps:

When it comes to packaging spectacle blind flanges, it’s important to ensure that they are properly protected and secured during transportation to prevent any damage. We will walk you through some of the key steps to follow when packaging spectacle blind flanges.

Step 1: Clean and Inspect the Flanges

Before packaging the spectacle blind flanges, it’s essential to clean them thoroughly to remove any dust, dirt, or debris that may have accumulated on them. You can use a cloth or brush to clean the flanges and inspect them to ensure they are free from any defects or damages.

Step 2: Choose the Right Packaging Material

The packaging material you choose should be sturdy and able to provide adequate protection to the flanges during transportation. Ideally, you should use a strong cardboard box or wooden crate that can withstand the weight and size of the spectacle blind flanges.

Step 3: Secure the Flanges

Once you have the packaging material ready, you need to secure the flanges to prevent them from moving around or getting damaged during transit. You can use bubble wrap, foam, or any other suitable cushioning material to protect the spectacle blind flanges from impact or shock.

Step 4: Label the Package

Labeling the package correctly is crucial to ensure that it reaches the intended destination without any confusion. You should clearly label the package with the recipient’s address, contact information, and any other necessary details.

Step 5: Arrange for Shipping

After the package is fully prepared and labeled, it’s time to arrange for shipping. You can use a reliable courier or shipping company to ensure that the package is delivered on time and in good condition.

Packaging spectacle blind flanges requires careful planning and attention to detail. By following the above steps, you can ensure that your flanges are properly protected and arrive at their destination safely. Remember to use high-quality packaging materials, secure the spectacle blind flanges properly, and label the package accurately to avoid any mishaps during transportation.
20230213040619 47357 - Spectacle Blind Flanges

Inspection and Measurement of spectacle blind flanges

There are several factors that need to be considered when inspecting and measuring spectacle blind flanges, including:

Material

The first thing to inspect in a spectacle blind flange is the material. The standard specifies that the flanges should be made from materials such as carbon steel, stainless steel, or alloy steel. The material should be free from any defects such as cracks, porosity, or inclusions that can affect the integrity of the flange.

Dimension

The next thing to inspect in a spectacle blind flange is its dimension. The standard specifies the dimensions of the flanges based on their nominal size and pressure rating. The flanges should be inspected for their inside and outside diameter, thickness, and overall dimensions to ensure they meet the requirements of the standard.

Surface Finish

The surface finish of a flange is also important. The standard specifies that the flanges should have a smooth and even surface finish to ensure proper sealing of the gasket. Any roughness or irregularities on the surface of the flange can lead to leaks in the piping system.

Bolt Hole Alignment

The bolt holes in a flange should be aligned properly to ensure the bolts can be inserted and tightened correctly. The bolt holes should be inspected to ensure they are in the correct position and are not misaligned.

Bolt Hole Size

The size of the bolt holes is also important. The standard specifies the size of the bolt holes based on the nominal size and pressure rating of the flange. The bolt holes should be inspected to ensure they are the correct size and are not damaged.

Bolt Hole Thread

The threads in the bolt holes are important to ensure the bolts can be screwed in and tightened properly. The threads should be inspected to ensure they are clean and free from any damage or defects.

To inspect and measure spectacle blind flanges, you will need a set of calipers or a micrometer to accurately measure the dimensions of the flange. It is also a good idea to have a torque wrench on hand to ensure that the bolts are tightened to the correct torque specification.

Installation and Maintenance of Spectacle Blind Flanges

Proper installation and maintenance of spectacle blind flanges are crucial to ensure their optimal performance and longevity. Follow these guidelines to maintain the integrity of your piping system:
Installation of figure 8 blind flanges
Proper installation of the figure 8 blind flange is critical to the safe and efficient operation of the piping system. For a successful installation, perform the following steps:

  • Inspect the flange: Prior to installation, inspect the figure 8 blind flange for any visible defects such as cracks, dents or warpage.

  • Prepare the pipe: Make sure the pipe is clean and free of debris. In addition, make sure the flange faces are clean and undamaged.

  • Position the flange: Align the figure 8 blind flange with the mating flange on the pipe or equipment, making sure the bolt holes are properly aligned.

  • Install Gasket: Place a suitable gasket between the flange faces to create a tight seal and prevent leakage. Ensure that the gasket material is compatible with the piping media and operating conditions.

  • Insert Bolts: Insert the appropriate bolts through the bolt holes and secure with nuts. Tighten bolts and nuts evenly in a crisscross pattern to ensure proper pressure distribution across the flange.

  • Rotate flange: Rotate the figure-of-8 blind flange to open (gasket side) or close (spade side) the pipe, depending on the desired flow configuration.

  • Verify installation: After installation, visually inspect the flanges for proper alignment and ensure that all bolts are tightened evenly.

Inspection of figure 8 blind flange
Periodically inspect the figure 8 blind flange for signs of wear, corrosion or damage. Monitor for any leaks and address them promptly to prevent further damage to the system.
Maintenance of figure 8 blind flange
Perform routine maintenance on the figure 8 blind flange, including cleaning, tightening bolts and replacing gaskets as necessary – shut down periodically for thorough inspection and maintenance of the entire piping system.
Replacement of figure 8 blind flange
Replace worn or damaged figure 8 blind flanges with new flanges that meet the original flange specifications. Ensure proper installation and alignment to maintain the integrity of the piping system.

Application of spectacle blind flanges

ASME B16.5 spectacle blind flanges are known to deliver exceptional performance and are generally developed to meet the demands. We offer a broad range of spectacle blind flanges through a worldwide network of stock-keeping branches.

This spectacle blind flange is used in various industries:

  • Spectacle blind flanges used in Oil and Gas Pipelines;

  • Spectacle blind flanges used in Chemical Industry;

  • Spectacle blind flanges used in Plumbing;

  • Spectacle blind flanges used in Heating;

  • Spectacle blind flanges used in Water Supply Systems;

  • Spectacle blind flanges used in Power Plants;

  • Spectacle blind flanges used in the Paper & Pulp Industry;

  • Spectacle blind flange uses in General Purpose Applications;

  • Spectacle blind flanges used in Fabrication Industry;

  • Spectacle blind flange uses in Food Processing Industry;

  • Spectacle blind flanges Use in Structural Pipe.

How do I choose between a spectacle blind flange, weld neck flange, and slip-on flange?

The choice between these flanges depends on your specific application requirements, such as pressure and temperature conditions, installation ease, maintenance needs, and budget constraints. Understanding the advantages and disadvantages of each flange type will help you make an informed decision.

How to purchase the correct spectacle blind flanges?

Are you in the market for spectacle blind flanges but don’t know where to start? Don’t worry, you’re not alone. With so many options available, it can be overwhelming to choose the right flanges for your project. We’ll go over some key factors to consider when purchasing spectacle blind flanges to ensure that you make the right decision.

Determine the Material Needed

The first step to purchasing the correct spectacle blind flanges is to determine the material you need. These flanges are available in a variety of materials, including carbon steel, stainless steel, and alloy steel. The choice of material will depend on the specific application and environmental conditions. If you’re unsure which material to choose, consult with a qualified engineer or supplier to help guide you in making the right decision.

Identify the Flange Face Type

Flange face types refer to the surface finish of a flange, and there are many different types of flange face finishes, including flat face (FF), raised face (RF), ring-type joint (SO), tongue and groove (T&G), male and female face (M&F). Each type of flange face has its unique characteristics and is suitable for different applications.
  • Flat face (FF): This type of flange face has a flat, smooth surface that is perpendicular to the axis of the pipe. It is typically used for low-pressure applications and when the sealing is achieved by a gasket.
  • Raised face (RF): This type of flange face has a raised ring on the surface that surrounds the bolt holes. The ring provides a surface for the gasket to rest on, which helps to create a better seal. It is commonly used in applications with moderate pressure.
  • Ring joint face (RTJ): This type of flange face has a specially designed groove to accommodate a metallic ring gasket. The groove is cut into the surface of the flange, and the gasket sits in the groove to create a tight seal. This type of flange face is typically used in high-pressure applications.

To identify a specific flange face type, you need to provide me with more information, such as the flange’s application, dimensions, and material.

Determine the spectacle blind flange Size and Pressure Class

Once you have identified the material and spectacle blind flange type, the next step is to determine the size and pressure class of the spectacle blind flange. spectacle blind flanges are available in various sizes and pressure ratings, and it’s crucial to select the correct size and pressure class to ensure that the flange can withstand the intended operating conditions. You should consult the system specifications and design to determine the appropriate size and pressure class.

Surface Finish

The flange face’s surface finish directly impacts the seal’s quality between the flanges. Common surface finishes include smooth, serrated, and grooved. Consult with the gasket manufacturer and consider the specific requirements of your application to select the most appropriate surface finish for your spectacle blind flanges.

Look for Quality and Certifications

It’s essential to ensure that the spectacle blind flanges you purchase are of high quality and come with the necessary certifications. Look for suppliers that have a reputation for delivering high-quality products, and check for relevant certifications, such as ISO 9001, API, and CE, to ensure that the flanges meet industry standards.

Consider the Price

While the price should not be the only factor to consider when purchasing spectacle blind flanges, it’s important to compare prices from different suppliers to ensure that you’re getting a fair price. However, remember that the cheapest option may not always be the best quality, so ensure that you’re not compromising on quality in pursuit of lower costs.

Purchasing the correct spectacle blind flanges can be challenging, but by considering the factors outlined in this post, you can ensure that you make an informed decision that meets your project requirements. Remember to consult with experts and compare suppliers to ensure that you’re getting a high-quality product at a fair price.

How to select spectacle blind flanges manufacturer?

Selecting the right manufacturer for spectacle blind flanges can be a daunting task. With so many options available, it’s easy to get overwhelmed and make the wrong choice. However, choosing the right manufacturer is critical to ensure that you get the best quality flanges that meet your specific needs. We provide some tips to help you select the right spectacle blind flanges manufacturer.

Quality of Products

The first factor to consider when selecting a spectacle blind flanges manufacturer is the quality of their products. You should look for a manufacturer that uses high-quality materials and follows strict quality control processes to ensure that their products meet the required standards.

Industry Experience

Another factor to consider is the manufacturer’s industry experience. Look for a manufacturer that has been in the industry for a significant period and has a proven track record of delivering high-quality products to their customers. An experienced manufacturer will have a better understanding of the market and the needs of their customers.

Production Capacity

It is also essential to consider the production capacity of the manufacturer. You should look for a manufacturer that has the capacity to produce the required quantity of flanges in a timely manner to meet your project’s needs.

Pricing

Pricing is another crucial factor to consider when selecting a spectacle blind flanges manufacturer. While it is essential to look for a manufacturer that offers competitive pricing, it is equally important to consider the quality of their products. Don’t compromise on the quality of the products for the sake of saving a few dollars.

Customer Service

The final factor to consider is the manufacturer’s customer service. Look for a manufacturer that has excellent customer service and is willing to assist you with any queries or concerns you may have. A manufacturer that values their customers will provide a better overall experience.

Choosing the right spectacle blind flanges manufacturer is essential to ensure you get high-quality products that meet your needs. Look for a manufacturer with quality certifications, experience, a good reputation, customization capabilities, and a competitive price. By following these tips, you will be able to find the right manufacturer for your flange needs.

Why Choose Jihua to Be Your Spectacle Blind Flange Supplier?

Jihua is a well-established and reputable manufacturer and supplier of spectacle blind flanges that has been providing high-quality products to customers worldwide for many years. Here are some reasons why you might choose Jihua to be your spectacle blind flange supplier:

  • High-quality products: Jihua is committed to providing high-quality spectacle blind flanges made from the best materials and manufactured to the highest standards. The company has strict quality control procedures in place to ensure that each product meets or exceeds customer expectations.
  • Competitive pricing: Jihua offers competitive pricing on its products, which means you can get high-quality spectacle blind flanges at an affordable price.
  • Wide range of products: Jihua offers a wide range of spectacle blind flanges, including ANSI, DIN, JIS, EN, and other international standards. This means you can find the right product to meet your specific needs.
  • Excellent customer service: Jihua is committed to providing excellent customer service and support to all of its customers. The company has a team of experienced professionals who are available to answer any questions or concerns you may have.
  • Fast delivery: Jihua understands the importance of timely delivery and works hard to ensure that all orders are shipped out quickly and efficiently.

Jihua is a reliable and trustworthy supplier of spectacle blind flanges that can meet your needs and exceed your expectations.

Export Country For spectacle blind flanges

MIDDLE EAST AFRICA NORspectacle blind AMERICA EUROPE ASIA SOUspectacle blind AMERICA
Saudi Arabia Nigeria Usa Russia India Argentina
Iran Algeria Canada Norway Singapore Bolivia
Iraq Angola Mexico Germany Malaysia Brazil
Uae South Africa Panama France Indonesia Chile
Qatar Libya Costa Rica Italy Thailand Venezuela
Bahrain Egypt Puerto Rica Uk Vietnam Colombia
Oman Sudan Trinidad And Tobago Spain South Korea Ecuador
Kuwait Equatorial Guinea Jamaica Ukraine Japan Guyana
Turkey The Republic Of Congo Bahamas Netherland Sri Lanka Paraguay
Yemen Gabon Denmark Belgium Maldives Uruguay
Syria Greece Bangladesh
Jordan Czech Republic Mayanmar
Cyprus Portugal Taiwan
Hungary Cambodia
Albania
Austria
Switzerland
Slovakia
Finland
Ireland
Croatia
Slovenia
Malta

FAQs

Q1: Can spectacle blind flanges be custom-made?

A1: Many manufacturers offer custom-made spectacle blind flanges to meet specific application requirements, such as unique sizes, materials, or pressure ratings.

Q2: How often should I inspect my spectacle blind flanges?

A2: The inspection frequency depends on system operating conditions, the environment, and the manufacturer’s recommendations. Generally, inspect spectacle blind flanges during scheduled maintenance or shutdowns.

Q3: Can I use a spectacle blind flange in a high-pressure application?

A3: Spectacle blind flanges are available in various pressure ratings to accommodate high-pressure applications. Choose a flange with a pressure rating suitable for your system.

Q4: How do I know if my spectacle blind flange needs to be replaced?

A4: Replace a spectacle blind flange if you notice signs of wear, corrosion, or damage during inspection or if it no longer meets the system’s pressure or temperature requirements.

Q5: Can I use a spectacle blind flange for isolation and flow control?

A5: Yes, spectacle blind flanges are versatile and can be used for isolation and flow control purposes, depending on the position of the spacer and spade. By rotating the spacer or spade, you can allow or block fluid flow through the piping system, making it an effective solution for both purposes.

Q6: Are there any alternatives to spectacle blind flanges for isolating sections of a piping system?

A6: Yes, alternatives to spectacle blind flanges include ball valves, gate valves, and line blinds. Each has advantages and disadvantages, so consider your application requirements and constraints when selecting the best solution.

Q7: What tools and equipment are needed to install and maintain spectacle blind flanges?

A7: Common tools and equipment for installing and maintaining spectacle blind flanges include torque wrenches, gaskets, bolt tensioners, flange spreaders, and lifting equipment. Always follow the manufacturer’s guidelines and safety precautions when working with these tools.

Q8: How do I determine the size of my spectacle blind flange?

A8: The size of the spectacle blind flange depends on your piping system’s pipe size, pressure, and temperature requirements. Consult the manufacturer’s guidelines or seek the advice of an experienced engineer to determine the appropriate size for your specific application.

Q9: Can spectacle blind flanges be used in extreme temperature conditions?

A9: Yes, spectacle blind flanges made from materials capable of withstanding extreme temperatures, such as stainless steel and alloy steel, or exotic materials like Inconel, Monel, and Hastelloy, can be used in high-temperature applications. Ensure that the chosen flange material meets the temperature requirements of your system.

Q10: How can I prevent corrosion on my spectacle blind flanges?

A10: To prevent corrosion, choose a spectacle blind flange material that offers adequate corrosion resistance for your specific application. Additionally, perform regular inspections and maintenance to detect and address any signs of corrosion early on.

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