Tube Expanding is the art of reducing a tube wall by compressing the O.D. of the tube against a fixed container such as rolling tubes into tube sheets, drums, ferrules or flanges..... CLICK HERE TO READ MORE!
Tube Installation Chart Tool Click on the following link to open the chart!
Torque controlled tube rolling increases productivity by achieving the desired tube wall reduction each and every time a tube is being expanded. Torque-controlled tube rolling compensates for variations in the tube wall thickness and the tube sheet hole dimensions.
Tube wall reduction is the percent the tube wall is reduced after the tube OD has contacted the tube sheet ID. The amount of tube wall reduction varies with the tube material, the tube sheet material and the design requirements of the unit. Several factors including pullout strength, freedom from leaks are considered in determining the optimum wall reduction.
Satisfactory joints are produced using the above listed percentage of tube wall reduction.
Step A – Measure tube sheet hole
Step B – Measure tube OD
Step C – Calculate clearance (A-B)
Step D – Measure tube OD
Step E – Calculate wall thickness (B-D)
Step F – Calculate 5% wall reduction (.05 x E)
Step G – Calculate finished rolled ID (C+D+F)
After the work sheet is finished, start setting up the torque control motor by test rolling the first of the five tubes. The first test roll must be done with the Airetrol or Electric tube rolling motor set for low torque to avoid over rolling.
Measure the tube ID after rolling the first tube. If more expansion is needed, increase the torque setting on the control and roll the second tube. Check the finished ID. This step may require repeating on tube three, but by the fifth tube you should have achieved your desired finished rolled ID of step G below. The tubes rolled to calibrate the tube wall reduction can now be re-rolled at the correct setting.
