ASME Flange Dimensional Reference Chart
1. B16.5 Standard Flanges (½" - 24")
| NPS | Class | OD | Thick. | Bolt Circle | # Bolts | Bolt Size | RF Height |
|---|---|---|---|---|---|---|---|
| ½" | 150# | 3.50" | 0.44" | 2.38" | 4 | ½" | 0.06" |
| 2" | 300# | 6.50" | 0.69" | 4.75" | 8 | ¾" | 0.06" |
| 8" | 600# | 15.00" | 1.38" | 11.75" | 12 | 1" | 0.25" |
| 24" | 900# | 33.00" | 2.75" | 29.50" | 20 | 1½" | 0.25" |
2. B16.47 Large Diameter (26" - 60")
| NPS | Series | Class | OD | Thick. | Bolt Circle | # Bolts |
|---|---|---|---|---|---|---|
| 26" | A | 150# | 40.50" | 1.88" | 37.00" | 48 |
| 36" | B | 300# | 50.50" | 2.25" | 47.50" | 44 |
| 48" | A | 600# | 66.00" | 3.50" | 61.50" | 56 |
| 60" | A | 900# | 82.00" | 4.25" | 76.50" | 64 |
3. B16.11 Threaded/Socket Weld (½" - 4")
| NPS | Class | OD | Thick. | Socket Depth |
|---|---|---|---|---|
| 1" | 3000# | 2.12" | 0.84" | 1.19" |
| 3" | 6000# | 5.25" | 1.62" | 2.38" |
4. Pressure-Temperature Ratings
Class 150 Carbon Steel (A105) Example:
| Temp (°F) | 100 | 400 | 600 | 800 |
|---|---|---|---|---|
| MAWP (psi) | 275 | 200 | 140 | 85 |
5. Material Thickness Comparison
| Class | NPS 12" Thickness |
|---|---|
| 150# | 1.06" |
| 300# | 1.50" |
| 600# | 2.06" |
6. Bolt Torque Specifications
| Bolt Size | Class 150 (ft-lbs) | Class 300 (ft-lbs) |
|---|---|---|
| ¾" | 120 | 210 |
| 1" | 220 | 380 |
| 1½" | 650 | 1,100 |
7. Flange Face Types & Dimensions
| Type | Height/Depth | Surface Finish |
|---|---|---|
| Raised Face | 0.06" (≤24") | 125-250 µin Ra |
| Ring Joint | R37 groove | 63 µin Ra max |
| Flat Face | 0.00" | 250-500 µin Ra |
8. Weight Calculator
For carbon steel flanges:
Weight (lbs) = 0.284 × π/4 × [(OD² - Bore²) × Thickness]
9. Industry Selection Guide
| Application | Recommended Flange |
|---|---|
| High-pressure steam | Weld Neck, Class 600# RTJ |
| Water treatment | Slip-On, Class 150# RF |
| Acid service | LJF with alloy stub end |
| Compressor piping | SW Class 3000# |
10. Inspection Checklist
Verify heat number and material certs
Check bore diameter (±1% tolerance)
Measure bolt hole alignment (±1°)
Confirm facing finish (visual comparison)
Validate NDE reports (RT/UT for critical)
Pro Tip: Always cross-reference with the latest ASME B16.5/B16.47 standards and manufacturer drawings for project-specific requirements. For large orders, request certified dimensional reports with actual measurements.
This chart combines both imperial and metric data where applicable (1" = 25.4mm). Dimensions may vary slightly by manufacturer - critical applications should use ASME-certified suppliers.
