Siyak Steel International is acknowledged as a manufacturer, exporter & suppliers of Spectacle Blind Flange & Stainless steel Flanges (Gr. 304, 304L, 316, 316L) available in a variety or grades, materials, and finishes, in metric and inch sizes. These Spectacle Blind Flange are manufacture in different Material of Flanges like SORF Flanges, Carbon Steel Spectacle Blind Flange, Stainless Steel Spectacle Blind Flange, Alloy Steel Spectacle Blind Flange, Duplex Steel Spectacle Blind Flange, Inconel Spectacle Blind Flange, Monel Spectacle Blind Flange, Hastelloy Spectacle Blind Flange, Copper Nickel Spectacle Blind Flange in India & Asia, conform to Slip On specifications.
A spectacle blind is a safety device used to isolate a section of line or piece of equipment when the line or equipment needs to be inspected or removed from service. It is different than a valve in that the blind is a permanent or long term isolation device.
A spectacle blind is machined from a single piece of metal that is cut to match the pipe size, fit between two pipe flanges and requires an additional gasket when it is installed. Also, the bolts will need to be lengthened depending on what piping class and size blind is used. The thickness of the spectacle blind is specified based on the line pressure and pipe size.
Spectacle Flanges, Spectacle Blind Flange Production Range
Spectacle Flanges Range
½” (15 NB) to 48″ (1200NB) in 150 LBS, 300 LBS, 600 LBS, 900 LBS, 1500 LBS, 2500 LBS ASA 150, ASA 300, PN 6,10,16,25, 40,64,100,160 ETC. Available with NACE MR 01-75
Stainless Steel Spectacle Flanges
Grade : 304, 304L, 304H, 309, 310, 310S, 316, 316Ti, 316 L, 317, 317L, 321, 347, 347 H, 409, 410, 410S, 420, 430L
Duplex Steel Spectacle Flanges
Grade : 2205 (UNS No. S31803), 2507 (UNS No. S32750)
Nickel Alloy Spectacle Flanges
Grade : Nickel 200 (UNS No. N02200), Nickel 201 (UNS No. N02201), Monel 400 (UNS No. N04400), Monel 500 (UNS No. N05500), Inconel 800 (UNS No. N08800), Inconel 825 (UNS No. N08825), Inconel 600 (UNS No. N06600), Inconel 625 (UNS No. N06625), Inconel 601 (UNS No. N06601), Hastelloy C 276 (UNS No. N10276), Alloy 20 (UNS No. N08020), Titanium (Grade I & II)
Copper Alloy Spectacle Flanges
Grade : UNS No. C 10100, 10200, 10300, 10800, 12000, 12200, 70600, 71500, UNS No. C 70600 (Cu -Ni- 90/10), C 71500 (Cu -Ni- 70/30)
Spectacle Flanges Standard
ANSI : ANSI B16.5, ANSI B16.47, MSS SP44, ANSI B16.36, ANSI B16.48
DIN : DIN2527, DIN2566, DIN2573, DIN2576, DIN2641, DIN2642, DIN2655, DIN2656, DIN2627, DIN2628, DIN2629, DIN 2631,
DIN2632, DIN2633, DIN2634, DIN2635, DIN2636, DIN2637, DIN2638, DIN2673
B.S : BS4504 , BS4504, BS1560, BS10
OTHER : PLATE, PLATE BLANK
The tables below show the most common sizes but are not exhaustive.
150 LBS
Class 150 SPECTACLE BLINDS
| NPS | OutsideA | InsideB | CenterlineC | Thicknesst | Web WidthW |
| 1/2 | 45 | 16 | 60 | 3 | 38 |
| 3/4 | 54 | 21 | 70 | 3 | 38 |
| 1 | 64 | 27 | 80 | 3 | 38 |
| 1¼ | 73 | 42 | 90 | 6.4 | 38 |
| 1½ | 83 | 48 | 100 | 6.4 | 38 |
| 2 | 102 | 61 | 120 | 6.4 | 51 |
| 2½ | 107 | 73 | 140 | 6.4 | 51 |
| 3 | 133 | 89 | 150 | 6.4 | 64 |
| 3½ | 159 | 102 | 175 | 9.7 | 64 |
| 4 | 172 | 114 | 190 | 9.7 | 64 |
| 5 | 194 | 141 | 215 | 9.7 | 76 |
| 6 | 219 | 168 | 240 | 12.7 | 76 |
| 8 | 276 | 219 | 300 | 12.7 | 76 |
| 10 | 337 | 273 | 360 | 15.7 | 102 |
| 12 | 406 | 324 | 430 | 19.1 | 102 |
| 14 | 448 | 356 | 475 | 19.1 | 108 |
| 16 | 511 | 406 | 460 | 22.4 | 108 |
| 18 | 546 | 457 | 580 | 25.4 | 114 |
| 20 | 603 | 508 | 635 | 28.4 | 121 |
| 24 | 714 | 610 | 750 | 31.8 | 140 |
| NPS | OutsideA | InsideB | CenterlineC | Thicknesst | Web WidthW |