Optimization of tube-to-tubesheet expansion process

Optimizing the tube-to-tubesheet expansion process requires attention to material matching and processing precision. Ensure the tubesheet hardness is higher than that of the tubes, and control the tube hole clearance within the range of 0.3 ± 0.05 mm to reduce stress concentration. Using hydraulic expansion instead of traditional mechanical expansion achieves uniform deformation and improves sealing performance.

In terms of process sequence, prioritize contact expansion to eliminate gaps, followed by strength expansion, to avoid the superposition of welding stresses. Optimize the expansion length, taking the smaller value between the nominal tubesheet thickness minus 3 mm or 50 mm, to ensure connection strength.

For quality control, verify the expansion effect through expansion rate testing (1-1.9%) and visual inspection. Utilize advanced expansion equipment, such as hydraulic bag type tube expanders, to improve process stability and reduce human error.