Finished Tube ID & Torque Calculator
The below calculator can help you determine your finished ID target and recommended torque for expansion.
Calculator
NOTE: The calculated values are estimated based on the available inputs. Actual values may vary due to tube thickness, material, tube sheet thickness, lubrication, operation condition, and/or operator technique. Best practices are to start with a lower torque setting and measure each tube to ensure proper wall reduction and finished ID is achieved.
BWG / Wall Thickness (Inch) Conversion Chart
| Tube Wall BWG | Tube Wall Inches |
|---|---|
| 0 | 0.340 |
| 1 | 0.300 |
| 2 | 0.284 |
| 3 | 0.259 |
| 4 | 0.238 |
| 5 | 0.220 |
| 6 | 0.203 |
| 7 | 0.180 |
| 8 | 0.165 |
| 9 | 0.148 |
| 10 | 0.134 |
| 11 | 0.120 |
| 12 | 0.109 |
| 13 | 0.095 |
| 14 | 0.083 |
| 15 | 0.072 |
| 16 | 0.065 |
| 17 | 0.058 |
| 18 | 0.049 |
| 19 | 0.042 |
| 20 | 0.035 |
| 21 | 0.032 |
| 22 | 0.028 |
| 23 | 0.025 |
| 24 | 0.022 |
| 25 | 0.020 |
| 26 | 0.018 |
Industry Recommended Wall Reductions
| Material | TEMA Standard Target % Wall Reduction | API-660 Target % Wall Reduction |
|---|---|---|
| Aluminum 3003 or 4004 | 4 – 6% | 5 – 7% |
| Aluminum 6061-T | 6 – 9% | 8 – 10% |
| Carbon Steel & low-alloy steel (max 9% Chromium) | 5 – 8% | 8% max* |
| Stainless Steel and high-alloy steel | 5 – 8% | 6% max* |
| Duplex Stainless Steels | 4 – 6% | Not Specified** |
| Titanium (and other nonferrous, work hardening materials) | 4 – 6% | 5% max* |
| Admiralty Brass (and other nonferrous, non-work hardening materials) | 4 – 9% | 8%* |
| Copper & Copper Alloys | 7 – 10% | Not Specified |
Additional Resources
Elliott Announces A Faster Way To Expand Small Heat Exchanger Tubes
Elliott Announces A Faster Way To Expand Small Heat Exchanger […]
Expanding Tubes In Heat Exchangers
Before you can start rolling, you will need to select the right expander for the job. Tube OD, and Wall/BWG will determine the size of the expander. However, there are some other factors to consider, such as tube projection, roll length, reach requirements, space constraints, and whether it’s minimum or average wall tubing.
How To Expand Welded Tubes
Expanding tubes after they have been welded can be frustrating for operators. If not rolled properly, tube material can build up and put stress on the weld. In extreme cases the tube material can build up so much that the expander can get stuck in the tube, delaying the job.
How To Prevent Tubes From Rotating When Rolling
Tube rolling occurs when the tube rotates due to inadequate friction between the tube OD and the hole in the tube sheet. This can cause increased expansion times and decrease the efficiency of the operator. Increasing the friction between the tube and tube sheet and or collar the tube will not rotate within the tube sheet. Increasing the friction can be done using several different methods: