Threaded Flange (Screwed)
Typical Threaded Flange Dimensions (ASME B16.5)
Threaded flanges are similar to slip-on flanges in outline but have a tapered internal thread (NPT or BSP). They are used in specialized applications where welding is restricted or for low-pressure services where pipe material is difficult to weld.
Technical Specifications
- Standard Threads: NPT (National Pipe Thread) is standard.
- Standards: ASME B16.5, DIN 2565/2566.
- Facing options: Raised Face (RF), Flat Face (FF), or RTJ.
- Pressure classes: 150, 300, 600, 900, 1500, 2500.
Dimensional Chart — ASME B16.5 Class 150 (mm)
All dimensions are in millimeters (mm). Table covers sizes from 1/2" to 24".
| NPS (Inches) | Outside Dia (O) | Thickness (C) | Hub Length (L) | Bolt Circle (W) | Bolt Holes (Qty) | Hole Dia |
|---|---|---|---|---|---|---|
| 1/2" | 90 | 11.2 | 16 | 60.3 | 4 | 15.9 |
| 3/4" | 100 | 12.7 | 16 | 69.9 | 4 | 15.9 |
| 1" | 110 | 14.3 | 17 | 79.4 | 4 | 15.9 |
| 1-1/4" | 115 | 15.9 | 21 | 88.9 | 4 | 15.9 |
| 1-1/2" | 125 | 17.5 | 22 | 98.4 | 4 | 15.9 |
| 2" | 150 | 19.1 | 25 | 120.7 | 4 | 19.1 |
| 2-1/2" | 180 | 22.3 | 29 | 139.7 | 4 | 19.1 |
Materials available
- Carbon steel: ASTM A105, A350 LF2 (zinc-plated or galvanized).
- Stainless steel: ASTM A182 F304/304L, F316/316L.
- Alloy steel: ASTM A182 F11, F22.
Note: Threaded flanges are generally limited to low-pressure systems and are not recommended for services with severe temperature cycles.