Yuhong Group supplied over 30,000 tons of stainless steel U-bend tubes to 35+ countries, serving critical sectors including nuclear power, petrochemical, and marine engineering. We provide complete heat exchanger tube bundles, U-tubes, finned tubes, and pressure vessel components—tube sheets, baffles, and heads—under a single supply chain, with third-party certifications including ABS, GL, DNV, PED, and ASME. Our technical team supports custom bending radii, stress relief protocols, and full NDE compliance per TEMA "C" and ASME Section VIII.
| Element | Composition (%) |
|---|---|
| Carbon (C) | ≤ 0.030 |
| Manganese (Mn) | ≤ 2.00 |
| Phosphorus (P) | ≤ 0.045 |
| Sulfur (S) | ≤ 0.030 |
| Silicon (Si) | ≤ 1.00 |
| Chromium (Cr) | 16.0 - 18.0 |
| Nickel (Ni) | 10.0 - 14.0 |
| Molybdenum (Mo) | 2.00 - 3.00 |
Heat and product analysis per ASME SA213 / ASTM A213 requirements.
U-bending is performed by cold working, with stress relief applied to the bend and extended legs via resistance heating, and inert gas (argon) purging during heat treatment to prevent internal oxidation. The bend radius is verified for outside diameter and wall thinning.
| Test | Purpose |
|---|---|
| Flattening Test | Evaluate ductility and soundness |
| Flaring Test | Assess ability to withstand expansion |
| Hardness Test (HRB/HBW) | Verify material consistency |
| Hydrostatic Test | Detect leakage |
| ET/UT | Detect surface and internal imperfections per ASME SA450/SA1016 |
| PMI | Confirm alloy grade |
| Component | Available Materials |
|---|---|
| Tube Sheets | SA266 Gr.2, SA516 Gr.70, SA350 LF2, Clad materials |
| Baffles | Carbon steel, SS304, SS316L |
| Heads / Channels | SA105, SA182 F304/F316, SA516 Gr.70 |
| Fasteners & Bolting | SA193 B7/B8, SA194 2H/8 |
ASME SA213 TP316L seamless U-tubes are specified for environments requiring:
| Option | Specification |
|---|---|
| Dimensions | OD 12.7mm - 50.8mm, wall 0.9mm - 6.0mm |
| Radius | Short or long radius, custom drawings |
| Tube Ends | Plain, beveled, or threaded |
| Finish | Pickled, bright annealed, or polished ID/OD |
| Packaging | Plywood cases, steel frames, export-ready |
Typical wall thinning at the intrados can range from 5-12%, depending on the bend radius and mandrel type. Yuhong Group monitors wall thickness at three positions (intrados, extrados, neutral axis) to ensure compliance.
Short radius elbows: center-to-end radius ≤ 1.5D. Minimum radius depends on tube OD, wall thickness, and the forming method used (plain or mandrel bending with internal support).
