Blind Flange (BLRF)
Technical Drawing: Blind Flange (BLRF) Profile
A Blind Flange is used to terminate the end of a piping system. It is a solid forging with no bore, designed to withstand substantial pressure. These flanges are also used as inspection covers or for future expansions of a pipeline.
Application and Standards
- Function: Sealing manholes, handholes, or pipe ends.
- Standards: ASME B16.5, DIN 2527, EN 1092-1.
- Pressure classes: 150 to 2500.
Dimensional Chart — ASME B16.5 Class 150 (mm)
Standard dimensions in millimeters for Class 150 Blind Flanges.
| NPS (Inch) | Outside Dia (O) | Thickness (C) | Bolt Circle (W) | Holes (Qty) | Hole Dia |
|---|---|---|---|---|---|
| 1/2" | 90 | 11.2 | 60.3 | 4 | 15.9 |
| 3/4" | 100 | 12.7 | 69.9 | 4 | 15.9 |
| 1" | 110 | 14.3 | 79.4 | 4 | 15.9 |
| 1-1/2" | 125 | 17.5 | 98.4 | 4 | 15.9 |
| 2" | 150 | 19.1 | 120.7 | 4 | 19.1 |
| 2-1/2" | 180 | 22.3 | 139.7 | 4 | 19.1 |
| 3" | 190 | 23.9 | 152.4 | 4 | 19.1 |
| 4" | 230 | 23.9 | 190.5 | 8 | 19.1 |
| 5" | 255 | 23.9 | 215.9 | 8 | 22.2 |
| 6" | 280 | 25.4 | 241.3 | 8 | 22.2 |
| 8" | 345 | 28.6 | 298.5 | 8 | 22.2 |
| 10" | 405 | 30.2 | 362.0 | 12 | 25.4 |
| 12" | 485 | 31.8 | 431.8 | 12 | 25.4 |
| 14" | 535 | 35.0 | 476.3 | 12 | 28.6 |
| 16" | 595 | 36.6 | 539.8 | 16 | 28.6 |
| 18" | 635 | 39.7 | 577.9 | 16 | 31.8 |
| 20" | 700 | 42.9 | 635.0 | 20 | 31.8 |
| 24" | 815 | 47.7 | 749.3 | 20 | 34.9 |
Materials available
- Carbon steel: ASTM A105, A350 LF2.
- Stainless steel: ASTM A182 F304/304L, F316/316L.
- High Yield: ASTM A694 F42, F52, F60, F65.
Blind flanges can be supplied with a tapped hole at the center for drainage or pressure gauges upon request.