Basic tube expansion formula
Basic expansion formula
The following formula will help you to choose the right expander and make the right expansion.
Percentage wall reduction is the most frequently used procedure to obtain the optimal mechanical joint between a Tube and Tube Sheet.
In order to calculate this reduction, we must consider the variances between the Tube OD, Tube Wall Thickness, and Tube Sheet Hole Diameter. We must also consider the differing types of materials being used for both Tubes and Tube Sheets, however, as a general rule, percentage wall reduction ranges between 4 – 10%.
The table illustrates the applicable percentage tube wall reductions according to the differing materials commonly used for both Tubes and Tube Sheets:
SHEET MATERIAL | TUBE MATERIAL | WALL REDUCTION |
|---|---|---|
Stainless steel | Stainless steel | 4-5% |
Steel | Stainless steel | 4-5% |
Steel | Steel | 7% |
Steel | Copper | 5% |
Copper | Copper | 10% |