In this article, I have covered the spectacle Blind Dimensions. A spectacle blind is used in piping for positive isolation of the section of a line or equipment during maintenance and shutdown.

ASME B16.48 standard that covers Line Blanks. This standard covers Spectacle Blind, Spades, and Spacers dimensions with pressure class 150, 300, 600, 900, 1500, and 2500 as listed in ASME B16.5.

Spectacle Blind Dimensions

spectacle blind dimensions

Class 150 Spectacle blind Dimensions

Size in Inch Size in MM Internal Dia. Outer Dia. Center to Center Thick. Web Width Web Thick. Hole Dia Spec. Blind Weight in Kg Paddle Blank Weight in kg Paddle Spacer Blank Weight in kg
1/2 15 16 45 60 3 38 2 15.875 0.07 0.03 0.03
3/4 20 21 54 70 3 38 2 15.875 0.1 0.05 0.04
1 25 27 64 80 3 38 2 15.875 0.14 0.07 0.06
1 1/4 32 42 73 90 6.4 38 4 15.875 0.35 0.21 0.14
1 1/2 40 48 83 100 6.4 38 4 15.875 0.46 0.27 0.18
2 50 61 102 120 6.4 51 4 19.05 0.68 0.41 0.26
2 1/2 65 73 107 140 6.4 51 4 19.05 0.7 0.46 0.24
3 80 89 133 150 6.4 64 4 19.05 1.1 0.71 0.39
3 1/2 90 102 159 175 9.7 64 5 19.05 2.44 1.54 0.9
4 100 114 172 190 9.7 64 5 19.05 2.81 1.8 1.01
5 130 141 194 215 9.7 76 5 22.225 3.37 2.29 1.08
6 150 168 219 240 12.7 76 7 22.225 5.39 3.82 1.57
8 200 219 276 300 12.7 76 10 22.225 8.32 6.07 2.25
10 250 273 337 360 15.7 102 12 25.4 15.04 11.19 3.84
12 300 324 406 430 19.1 102 15 25.4 26.95 19.77 7.18
14 350 356 448 475 19.1 108 15 28.575 32.94 24.07 8.87
16 400 406 511 540 22.4 108 17 28.575 50.27 36.73 13.54
18 450 457 546 580 25.4 114 20 31.75 61.79 47.55 14.23
20 500 508 603 635 28.4 121 22 31.75 83.67 64.85 18.82
24 600 610 714 750 31.8 140 24 34.925 129.3 101.8 27.49

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Class 300 Spectacle blind Flange Dimensions

Size in Inch Size in MM Internal Dia. Outer Dia. Center to Center Thick. Web Width Web Thick. Hole Dia Spec. Blind Weight in Kg Paddle Blank Weight in kg Paddle Spacer Blank Weight in kg
1/2 15 16 51 65 6.4 38 4 15.875 0.19 0.1 0.09
3/4 20 21 64 80 6.4 38 4 19.05 0.31 0.16 0.14
1 25 27 70 90 6.4 38 4 19.05 0.36 0.19 0.16
1 1/4 32 42 79 100 6.4 38 4 19.05 0.43 0.25 0.17
1 1/2 40 48 92 115 6.4 38 4 22.225 0.58 0.34 0.24
2 50 61 108 125 9.7 51 5 19.05 1.19 0.71 0.48
2 1/2 65 73 127 150 9.7 51 5 22.225 1.64 0.98 0.65
3 80 89 146 170 9.7 64 5 22.225 2.11 1.29 0.81
3 1/2 90 102 162 185 12.7 64 7 22.225 3.35 2.09 1.26
4 100 114 178 200 12.7 64 7 22.225 4.01 2.52 1.49
5 130 141 213 235 15.7 76 8 22.225 6.98 4.47 2.51
6 150 168 248 270 15.7 76 8 22.225 9.34 6.06 3.28
8 200 219 305 330 22.4 76 17 25.4 19.42 13.08 6.33
10 250 273 359 385 25.4 102 20 28.575 29.22 20.55 8.66
12 300 324 419 450 28.4 102 22 31.75 43.9 31.31 12.58
14 350 356 483 515 31.8 108 24 31.75 67.86 46.58 21.27
16 400 406 536 570 38.1 108 29 34.925 98.04 68.74 29.3
18 450 457 594 630 41.1 114 31 34.925 128.23 91.06 37.16
20 500 508 651 685 44.5 121 34 34.925 164.75 118.43 46.31
24 600 610 772 810 50.8 140 39 41.275 261.55 190.13 71.42

Class 600 Spectacle blind Flange Dimensions

Size in Inch Size in MM Internal Dia. Outer Dia. Center to Center Thick. Web Width Web Thick. Hole Dia Spec. Blind Weight in Kg Paddle Blank Weight in kg Paddle Spacer Blank Weight in kg
1/2 15 16 51 65 6.4 38 4 15.875 0.19 0.1 0.09
3/4 20 21 64 80 6.4 38 4 19.05 0.31 0.16 0.14
1 25 27 70 90 6.4 57 4 19.05 0.36 0.19 0.16
1 1/4 32 37 79 100 9.7 57 5 19.05 0.67 0.38 0.29
1 1/2 40 43 92 115 9.7 67 5 22.225 0.91 0.51 0.4
2 50 55 108 125 9.7 57 5 19.05 1.23 0.71 0.52
2 1/2 65 67 127 150 12.7 67 7 22.225 2.21 1.28 0.92
3 80 83 146 170 12.7 67 7 22.225 2.85 1.7 1.15
3 1/2 90 96 159 185 15.7 76 8 25.4 4.07 2.49 1.58
4 100 108 191 215 15.7 76 8 25.4 6.04 3.59 2.44
5 130 135 238 265 19.1 86 10 28.575 11.4 6.79 4.6
6 150 162 264 290 22.4 86 12 28.575 15.91 9.8 6.11
8 200 212 318 350 28.4 95 22 31.75 28.05 18.03 10.01
10 250 265 397 430 35.1 105 27 34.925 54 34.74 19.26
12 300 315 454 490 41.1 105 31 34.925 80.78 53.2 27.58
14 350 346 489 525 44.5 114 34 38.1 100.19 66.82 33.36
16 400 397 562 605 50.8 124 39 41.275 151.24 100.76 50.48
18 450 448 610 655 53.8 133 41 44.45 183.62 125.71 57.9
20 500 497 679 725 63.5 133 48 44.45 269.2 183.85 85.35
24 600 597 787 840 73.2 152 55 50.8 405.6 284.72 120.88

Class 900 Spectacle blind Flange Dimensions

Size in Inch Size in MM Internal Dia. Outer Dia. Center to Center Thick. Web Width Web Thick. Hole Dia Spec. Blind Weight in Kg Paddle Blank Weight in kg Paddle Spacer Blank Weight in kg
1/2 15 16 60 80 6.4 38 4 22.225 0.27 0.14 0.13
3/4 20 21 67 90 6.4 41 4 22.225 0.34 0.18 0.16
1 25 27 76 100 6.4 57 4 25.4 0.43 0.23 0.2
1 1/4 32 37 86 110 9.7 57 5 25.4 0.81 0.45 0.36
1 1/2 40 43 95 125 9.7 67 5 28.575 0.98 0.54 0.43
2 50 55 140 165 12.7 57 7 25.4 2.88 1.56 1.32
2 1/2 65 67 162 190 12.7 67 7 28.575 3.82 2.09 1.73
3 80 83 165 190 15.7 67 8 25.4 4.68 2.68 2
4 100 108 203 235 19.1 76 10 31.75 8.48 4.94 3.54
5 130 135 244 280 22.4 86 12 34.925 14.18 8.37 5.81
6 150 162 286 320 25.4 86 13 31.75 21.9 13.04 8.86
8 200 212 356 395 35.1 95 27 38.1 45.96 27.93 18.02
10 250 265 432 470 41.1 105 31 38.1 78.21 48.16 30.04
12 300 315 495 535 47.8 105 36 38.1 117.31 73.55 43.76
14 350 346 518 560 53.8 114 41 41.275 140.86 90.65 50.2
16 400 397 572 615 60.5 124 46 44.45 188.73 124.31 64.42
18 450 448 635 685 66.5 133 50 50.8 252.97 168.39 84.57
20 500 497 696 750 73.2 133 55 53.975 331.81 222.68 109.13
24 600 597 835 900 88.9 152 67 66.675 579.52 389.25 190.27

Class 1500 Spectacle blind Flange Dimensions

Size in Inch Size in MM Internal Dia. Outer Dia. Center to Center Thick. Web Width Web Thick. Hole Dia Spec. Blind Weight in Kg Paddle Blank Weight in kg Paddle Spacer Blank Weight in kg
1/2 15 16 61 80 6.4 38 4 22.225 0.28 0.14 0.13
3/4 20 21 67 90 9.7 41 5 22.225 0.52 0.27 0.24
1 25 27 76 100 9.7 64 5 25.4 0.65 0.35 0.3
1 1/4 32 35 86 110 9.7 64 5 25.4 0.82 0.45 0.37
1 1/2 40 41 95 125 12.7 70 7 28.575 1.3 0.71 0.58
2 50 53 140 165 12.7 70 7 25.4 2.9 1.56 1.33
2 1/2 65 63 162 190 15.7 76 8 28.575 4.78 2.58 2.19
3 80 78 172 205 19.1 76 10 31.75 6.36 3.54 2.81
4 100 102 206 240 22.4 89 12 34.925 10.47 5.96 4.5
5 130 128 251 290 28.4 89 15 41.275 19.55 11.23 8.31
6 150 154 279 320 35.1 89 18 38.1 29.08 17.15 11.93
8 200 203 349 395 41.1 102 31 44.45 52.23 31.43 20.8
10 250 255 432 480 50.8 114 39 50.8 98.33 59.53 38.79
12 300 303 518 570 60.5 114 46 53.975 169.01 101.94 67.06
14 350 333 575 635 66.5 127 50 60.325 229.84 138.07 91.76
16 400 381 638 705 76.2 133 58 66.675 320.1 194.78 125.32
18 450 429 702 775 85.9 146 65 73.025 432.4 265.84 166.56
20 500 478 752 830 95.3 152 72 79.375 540.14 338.44 201.7
24 600 575 899 990 111.3 178 84 92.075 898.71 564.9 333.8

Class 2500 Spectacle blind Flange Dimensions

Size in Inch Size in MM Internal Dia. Outer Dia. Center to Center Thick. Web Width Web Thick. Hole Dia Spec. Blind Weight in Kg Paddle Blank Weight in kg Paddle Spacer Blank Weight in kg
1/2 15 16 67 90 9.7 38 5 22.225 0.53 0.27 0.25
3/4 20 21 73 95 9.7 41 5 22.225 0.62 0.32 0.29
1 25 27 83 110 9.7 64 5 25.4 0.79 0.41 0.37
1 1/4 32 35 102 130 12.7 64 7 28.575 1.56 0.82 0.73
1 1/2 40 41 114 145 15.7 70 8 31.75 2.39 1.28 1.11
2 50 53 143 170 15.7 70 8 28.575 3.75 2.01 1.73
2 1/2 65 63 165 195 19.1 76 10 31.75 6.05 3.26 2.78
3 80 78 194 230 22.4 76 12 34.925 9.73 5.29 4.43
4 100 102 232 275 28.4 89 22 41.275 17.34 9.59 7.74
5 130 128 276 325 35.1 89 27 47.625 29.97 16.79 13.17
6 150 154 314 370 41.1 89 31 53.975 44.77 25.44 19.32
8 200 198 384 440 53.8 102 41 53.975 86.39 49.82 36.57
10 250 248 473 540 66.5 114 50 66.675 161.18 93.43 67.74
12 300 289 546 620 79.2 114 60 73.025 255.01 148.27 106.73

Disclaimer –  Please check with ASME B16.5 Before using.

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Varun Patel - HardHat Engineer

About Author: Varun Patel is a Mechanical Engineer and an Oil & Gas Professional. He is a Certified Project Management Professional – PMP® from PMI® USA. With over nineteen years of experience, he has worked with Fortune 500 Oil & Gas Companies. Know more.