📐 Flange Standards Compared
| Standard | Region | Key Features | Common Pressure Ratings | Notes |
|---|---|---|---|---|
| ASME B16.5 | USA (ANSI/ASME) | Inch-based, widely used in oil, gas, and chemical sectors | Class 150 to Class 2500 | Up to 24" |
| ASME B16.47 | USA | For flanges 26"–60", divided into Series A & B | Class 75 to Class 900 | Large diameters |
| DIN (e.g., 2633) | Germany | Metric-based, legacy German standards | PN 6 to PN 400 | Being replaced by EN |
| EN 1092-1 | Europe (CEN) | Replaces many DIN standards, standardized across EU | PN 2.5 to PN 400 | Most widely used in Europe |
| JIS B2220 | Japan | Metric-based, Japanese industrial standard | 5K, 10K, 16K, 20K, 30K | Common in Asia-Pacific |
| GOST 12820/12821 | Russia/CIS | Russian standard, similar to DIN | PN 10 to PN 100 | Often used in CIS countries |
| BS 4504 | UK (British Standard) | Based on DIN, mostly replaced by EN | PN 2.5 to PN 40 | Legacy use |
| AWWA C207 | USA (Water Works) | Flanges for low-pressure water systems (steel ring flanges) | Class B to E | Municipal pipelines |
| ISO 7005-1/2/3 | International | Global metric standard based on EN and DIN | PN 2.5 to PN 400 | For harmonization worldwide |
🔄 Key Differences
| Feature | ASME (B16.5) | EN 1092-1 / DIN | JIS B2220 |
|---|---|---|---|
| Units | Inches (Imperial) | Metric | Metric |
| Pressure Designation | Class (150, 300, etc.) | PN (10, 16, 40, etc.) | K (5K, 10K, etc.) |
| Face Types | RF, FF, RTJ | Type A/B/C, etc. | RF/FF |
| Bolt Patterns | Unique to ASME | Metric bolt holes | Metric bolt holes |
| Usage | Global (esp. USA) | Europe, globally adopted | Japan, some Asia regions |
✅ Tips for Selecting the Right Flange Standard
Project Location: Use local or customer-specified standards.
System Compatibility: Ensure bolt pattern and pressure class match existing system.
Interchangeability: Be cautious-similar sizes may not be interchangeable between standards.
Industry Preference: Oil & gas = ASME; municipal = AWWA; European industries = EN.
