American Threaded Flange
- Standard: ASME B16.5
- NPS: ½”~2”
- Material: carbon steel, stainless steel
- Temperature: Class 150, Class 300
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American Standard threaded flanges (NPS≤2″) connect pipes by internal and external thread screwing without welding, suitable for low pressure, clean or frequent disassembly conditions. The material covers carbon steel, stainless steel and alloy steel, in accordance with ASME B16.5 standard, the sealing relies on gasket and bolt fastening, easy installation but need to pay attention to the thread precision and thermal expansion limit.
American Threaded Flange Size Chart
Conforms to ASME B16.5
Class 150 Size
| NPS | DN | OD | Bolt hole center circle diameter | Number of bolt holes × hole diameter | Flange thickness (T) |
| ½” | DN15 | 98 mm | 70 mm | 4×16 mm | 9.6 mm3 |
| 1″ | DN25 | 120 mm | 89 mm | 4×16 mm | 12.7 mm3 |
| 1½” | DN40 | 127 mm | 98.5 mm | 4×16 mm | 15.9 mm3 |
| 2″ | DN50 | 152 mm | 127 mm | 4×19 mm | 17.5 mm38 |
Class 300 Size
| NPS | DN | OD | Bolt hole center circle diameter | Number of bolt holes × hole diameter | Flange thickness (T) |
| ½” | DN15 | 114 mm | 82.5 mm | 4×19 mm | 14 mm48 |
| 1″ | DN25 | 133 mm | 98.5 mm | 8×19 mm | 16 mm48 |
| 1½” | DN40 | 165 mm | 127 mm | 8×19 mm | 20.7 mm38 |
| 2″ | DN50 | 190 mm | 152.5 mm | 8×22 mm | 24 mm48 |
Low pressure scenarios (≤1.0 MPa): Class 150 is preferred for thinner thickness and lower cost.
Frequent dismantling scenarios: metal-wound gaskets or PTFE gaskets are required to avoid leakage from thread abrasion.
High temperature scenario (>200℃): it is recommended to use butt weld flange (WN) or socket weld flange (SW).