A Blind flange derived it name blind as it is used to blank off a line it does not have a inside bore it is mounted on corresponding flange with the help of Bolt holes matching with that of the other flange. Blind flanges are widely used in testing facilities of vales or Lines being inspected for leakage etc. A blind flange can also be used to close one end of open line. We have the expertise to manufacture Blind flange for varied applications and varied line sizes and materials.
| DIMENSIONS OF CLASS 300 FLANGES (ANSI B 16.5) (in mm) | ||||||||||||||||
| Nominal | Flange | Dia of | Dia of Bolt Holes | No. of | Thk of Flange | Diameter at Weld Bevel | Dia of Hub | Length Through Hub | Bore 'B' | Dia of | Depth of | Length | ||||
| Pipe Size | Dia | Bolt Circle | 'D' | Holes | 'C' | 'E' | R/F | Socket | of | |||||||
| 'O' | 'A' | S/O & S/W | W/N | L/J | S/O & S/W | L/J | R | F | Threading | |||||||
| Y | Y | Y | B | B | ||||||||||||
| 1/2'' | 15 | 95.2 | 66.7 | 15.9 | 4 | 14.3 | 21.3 | 38.1 | 22.2 | 52.4 | 22.2 | 22.3 | 22.9 | 34.9 | 9.5 | 15.9 |
| 3/4'' | 20 | 117.5 | 82.5 | 19 | 4 | 15.9 | 26.7 | 47.6 | 25.4 | 57.1 | 25.4 | 27.7 | 28.2 | 42.9 | 11.1 | 15.9 |
| 1'' | 25 | 123.8 | 88.9 | 19 | 4 | 17.5 | 33.5 | 54 | 27 | 61.9 | 27 | 34.5 | 35 | 50.8 | 12.7 | 17.5 |
| 1 ¼'' | 32 | 133.3 | 98.4 | 19 | 4 | 19 | 42.2 | 63.5 | 27 | 65.1 | 27 | 43.2 | 43.7 | 63.5 | 14.3 | 20.6 |
| 1 ½'' | 40 | 155.6 | 114.3 | 22.2 | 4 | 20.6 | 48.3 | 69.8 | 30.2 | 68.3 | 30.2 | 49.5 | 50 | 73 | 15.9 | 22.2 |
| 2'' | 50 | 165.1 | 127 | 19 | 8 | 22.2 | 60.4 | 84.1 | 33.3 | 69.8 | 33.3 | 62 | 62.5 | 92.1 | 17.5 | 25.4 |
| 2 ½'' | 65 | 190.5 | 149.2 | 22.2 | 8 | 25.4 | 73.1 | 100 | 38.1 | 76.2 | 38.1 | 74.7 | 75.4 | 104.8 | 19 | 28.6 |
| 3'' | 80 | 209.5 | 168.3 | 22.2 | 8 | 28.6 | 88.9 | 117.5 | 42.9 | 79.4 | 42.9 | 90.7 | 91.4 | 127 | 20.6 | 30.2 |
| 3 ½'' | 90 | 228.5 | 184.2 | 22.2 | 8 | 30.2 | 101.6 | 133.4 | 44.5 | 81 | 44.5 | 103.4 | 104.1 | 140 | 20.6 | 31.7 |
| 4'' | 100 | 254 | 200 | 22.2 | 8 | 31.8 | 114.3 | 146 | 47.6 | 85.7 | 47.6 | 116.1 | 116.8 | 157.2 | 23.8 | 33.3 |
| 5'' | 125 | 279.4 | 234.9 | 22.2 | 8 | 34.9 | 141.2 | 177.8 | 50.8 | 98.4 | 50.8 | 143.8 | 144.5 | 185.7 | - | 36.5 |
| 6'' | 150 | 317.5 | 269.9 | 22.2 | 12 | 36.5 | 168.4 | 206.4 | 52.4 | 98.4 | 52.4 | 170.7 | 171.4 | 215.9 | - | 39.7 |
| 8'' | 200 | 381 | 330.2 | 25.4 | 12 | 41.3 | 219.2 | 260.3 | 61.9 | 111.1 | 61.9 | 221.5 | 222.2 | 269.9 | - | 44.4 |
| 10'' | 250 | 444.5 | 387.3 | 28.6 | 16 | 47.6 | 273 | 320.7 | 66.7 | 117.5 | 95.2 | 276.3 | 277.4 | 323.8 | - | 49.2 |
| 12'' | 300 | 520.7 | 450.8 | 31.7 | 16 | 50.8 | 323.8 | 374.6 | 73 | 130.2 | 101.6 | 327.1 | 328.2 | 381 | - | 55.6 |
| 14'' | 350 | 584.2 | 514.3 | 31.7 | 20 | 54 | 355.6 | 425.4 | 76.2 | 142.9 | 111.1 | 359.1 | 360.2 | 412.7 | - | 57.1 |
| 16'' | 400 | 647.7 | 571.5 | 34.9 | 20 | 57.2 | 406.4 | 482.6 | 82.5 | 146 | 120.6 | 410.5 | 411.2 | 469.9 | - | 63.5 |
| 18'' | 450 | 711.2 | 628.5 | 34.9 | 24 | 60.3 | 457.2 | 533.4 | 88.9 | 158.7 | 130.2 | 461.8 | 462.3 | 533.4 | - | 68.3 |
| 20'' | 500 | 774.7 | 685.8 | 34.9 | 24 | 63.5 | 508 | 587.4 | 95.2 | 161.9 | 139.7 | 513.1 | 514.3 | 584.2 | - | 73 |
| 24'' | 600 | 914.4 | 812.8 | 41.3 | 24 | 69.8 | 609.6 | 701.7 | 106.4 | 168.3 | 152.4 | 615.9 | 615.9 | 692.1 | - | 82.5 |
Note : Thickness 'C' is inclusive of Raised Face Thickness of 1.65 MM. For Class 300
