The tube bundle is the removable or fixed core assembly within a shell and tube heat exchanger, comprising tubes, tube sheets, baffles, tie rods, and spacers. This assembly is the primary heat transfer interface between two fluid streams - one flowing inside the tubes (tube side) and the other across the external tube surfaces (shell side).
The tube bundle is designed and manufactured per TEMA Class C (commercial), B (chemical), or R (refinery), ASME Section VIII Division 1 or Division 2, and GB/T 151 for domestic applications. This product is supplied as a replacement bundle, a spare bundle, or as part of a new heat exchanger assembly.
| Parameter | Range | Standard / Note |
|---|---|---|
| Tube OD | 12.7mm - 50.8mm (1/2" to 2") | Smaller OD for higher pressure; larger OD for fouling service |
| Tube wall thickness | 0.9mm - 5.0mm | Selected per ASME VIII-1 UG-27 for internal pressure; gauge thickness per ASTM B730 |
| Tube length (straight) | 1.5m - 12.0m | Standard TEMA lengths: 2.44m, 4.88m, 6.10m, 9.75m |
| Tube pitch | 1.25× - 2.0× tube OD | Triangular pitch (30°) for higher heat transfer; square pitch (90°) for mechanical cleaning access |
| Tube arrangement | Triangular (30°/60°) / Square (90°/45°) | Triangular gives highest surface area per shell cross-section; square allows rod or brush cleaning access to shell side |
| Parameter | Range / Value | Standard / Note |
|---|---|---|
| Thickness | 20mm - 300mm | Per TEMA RCB-4.3 - selected to withstand tube-to-tubesheet joint loads and shell/tube side pressure independently |
| Hole diameter tolerance | H11 (e.g., Ø25.2mm +0.13/0) | Per ISO 286 / TEMA standard |
| Hole finish | Ra ≤ 1.6μm (expanded) / Ra ≤ 3.2μm (welded) | Expansion requires finer finish to achieve pull-out strength |
| Ligament (bridge between holes) | Minimum 0.8× hole diameter | Per ASME VIII-1 Appendix A - to prevent tube sheet deformation |
| Tube sheet material | CS / SS clad / alloy / solid | Selected per tube-side and shell-side fluid compatibility |
| Parameter | Range / Value | Standard / Note |
|---|---|---|
| Baffle type | Segmental (20-35% cut) / Double segmental / Helical / No-baffle (full supports only) | Segmental cut percentage selected per TEMA for cross-flow velocity |
| Baffle spacing | 0.2× - 1.0× shell ID | Determined by unsupported tube length limit and required cross-flow velocity |
| Maximum unsupported tube length | CS: ≤ 36× tube OD; SS: ≤ 30× tube OD | Per TEMA RCB-4.2 to prevent tube vibration and sag |
| Baffle thickness | 3.0mm - 16mm | Based on shell side pressure differential and support span |
| Tie rod diameter | M8 - M24 (or equivalent imperial) | Minimum 4 rods per bundle; diameter selected per TEMA RCB-4.6 to support bundle weight |
| Joint Type | Method | Pull-Out Strength (Min) | Applicable Service | Inspection Method |
|---|---|---|---|---|
| Expanded only | Hydraulic expansion at 160-220 MPa, hold 5-8s | ≥ 20 MPa (CS) / ≥ 25 MPa (SS) | Non-toxic, non-cyclic service; clean fluids | Hydrostatic test + pull-out test on first article |
| Welded only (seal weld) | GTAW (TIG) fillet weld leg 1.5-2.0mm | N/A (mechanical retention from weld only) | High-pressure gas, hydrogen service | 100% PT per ASME VIII-1 UW-51 |
| Weld + expand (combined) | Seal weld + hydraulic expansion at 160-200 MPa | ≥ 25 MPa | Cyclic thermal service (> 500 cycles/year), high pressure, toxic fluids | 100% PT + hydrotest + pull-out test on first article |
| Material | Spec | Temp Range | Chloride Limit | Application Notes |
|---|---|---|---|---|
| Carbon steel SA-179 / SA-106 Gr.B | ASTM A179 / A106 | -20°C to +425°C | Not applicable | Water, oil, steam, clean hydrocarbons |
| Carbon steel 20# | GB 8163 | -20°C to +425°C | Not applicable | Domestic standard equivalent to SA-106 |
| Stainless 304L / 304 | ASTM A213 TP304L | -196°C to +600°C | ≤ 200ppm | Mildly corrosive fluids, clean steam, food grade |
| Stainless 316L / 316 | ASTM A213 TP316L | -196°C to +500°C | ≤ 200ppm | Organic acids, salt solutions, chloride-containing hydrocarbons |
| Duplex 2205 | ASTM A789 S32205 | -40°C to +280°C | ≤ 300ppm at 80°C | Offshore, seawater, chlorides, CO₂/H₂S service |
| Titanium Gr.2 | ASTM B338 | -40°C to +230°C | Up to 20,000ppm | Seawater, brine, high-chloride environments |
| Alloy 800H / 825 / 625 | ASTM B163 | -196°C to +600°C | Up to 500ppm | High-temperature corrosive service, sour gas, amine units |
| Parameter | Range | Notes |
|---|---|---|
| Tube-side design pressure | Vacuum (-0.1 MPa) to 35 MPa | Higher pressure requires seamless tube and heavy wall tube sheet |
| Shell-side design pressure | Vacuum (-0.1 MPa) to 10 MPa (standard) | Dependent on shell construction and flange rating |
| Tube-side design temperature | -196°C to +600°C | Material dependent; cryogenic service requires impact testing per ASME VIII-1 UG-84 |
| Shell-side design temperature | -40°C to +450°C | Dependent on shell material and gasket type |
| Tube-side fluid | Liquids, gases, condensing vapors, two-phase mixtures | Compatible with tube material |
| Shell-side fluid | Liquids, gases, condensing vapors, boiling fluids | Compatible with shell material (tube OD material if direct contact) |
| Maximum tube-side velocity (liquid) | 2.5 - 4.5 m/s | Carbon steel max 3.0 m/s; titanium max 4.5 m/s per TEMA erosion velocity guideline |
| Maximum tube-side velocity (gas) | 15 - 30 m/s | Limited by vibration and pressure drop |
| Tube-side Reynolds number target | ≥ 10,000 (turbulent) for clean service | Lower values require increased surface area or lower thermal performance |
When ordering a replacement bundle, provide:
