| Component | Material Specification | Standard | Key Properties |
|---|---|---|---|
| Heat Exchanger Tubes | SA179 Carbon Steel | ASME SA-179/SA-179M | Cold-drawn seamless, min. wall thickness, heat treated at ≥650°C after final pass |
| Tube Sheet | SA266 Gr.2N | ASME SA-266 | Normalized forged carbon steel, improved uniform mechanical properties |
| Baffles | SA516 Gr.70 | ASME SA-516 | Pressure vessel quality steel, directs shell-side flow |
| Tie Rods & Spacers | SA193 B7 (or equivalent) | ASME SA-193 | Maintains baffle alignment and bundle rigidity |
| Test Type | Method / Reference Standard | Inspection Objective |
|---|---|---|
| Hydrostatic Test | ASME Section VIII UG-99 | Verify tube-to-tubesheet joint tightness and pressure boundary integrity |
| Mechanical Testing | Tensile, flattening, flaring, expanding tests per SA-450 | Confirm SA179 mechanical properties meet ≥325 MPa tensile, ≥180 MPa yield, ≥35% elongation |
| Hardness Inspection | HRB ≤ 72 (SA179) | Ensure no excessive work hardening from cold drawing |
| Non-Destructive Examination | UT, PT (as specified) | Detect surface and subsurface defects on tubes and tubesheet |
| Dimensional Inspection | Per approved drawing and SA-450 tolerances | Verify OD, wall thickness, tube pitch, and bundle dimensions |
| Material Traceability | Heat number verification, MTC | Confirm chemical composition: C 0.06-0.18%, Mn 0.27-0.63%, P ≤0.035%, S ≤0.035% |
