Yuhong Group Co., Ltd. engineers and supplies complete finned tube bundles for air-cooled heat exchangers (ACHEs), alongside shell & tube heat exchangers, pressure vessels, and replacement components including U-tubes, finned tubes, tubesheets, baffles, and heads. All products are fabricated under ASME U-Stamp certification and comply with API 661, PED, and international classification society requirements.
The finned tube bundle is the core heat exchange component of an air cooler. This bundle features ASME SA179 seamless low-carbon steel tubes as the base carrier, with Al1060 aluminum fins mechanically embedded via G-type (embedded) finning technology. The G-type process involves precision-machining helical grooves on the tube outer surface, then cold-working aluminum strip into the grooves under tension to create a permanent, near-zero-contact-resistance bond. This design delivers 5-10× the heat transfer surface area of bare tubes while maintaining mechanical integrity at elevated service temperatures.
| Component | Material / Standard | Key Specifications |
|---|---|---|
| Base Tubes | ASME SA179 seamless cold-drawn low-carbon steel | OD: 16-63 mm; wall thickness per ASME SA179 minimum-wall requirements |
| Fins | Aluminum 1060 (Al1060) | Fin height: 15.88 mm; fin thickness: ~0.4 mm |
| Tube Sheets | Carbon steel / alloy steel (per design) | ASME Sec. VIII Div.1 compliant |
| Headers / Manifolds | Carbon steel (coated) or stainless steel | Designed per API 661 |
| Structural Frame | Hot-dip galvanized or stainless steel | Supports wind, seismic, and operational loads |
All finned tube bundles undergo inspection and testing in accordance with ASME Code requirements and API 661 guidelines:
| Test Type | Standard / Method | Acceptance Criteria |
|---|---|---|
| Hydrostatic Test | ASME Sec. VIII Div.1 | Minimum 10-25 MPa, no leakage |
| Eddy Current Testing (ECT) | ASME SA179 / ASTM A179 | Detects surface and subsurface defects |
| Dimensional Inspection | ISO 9309 / ASTM B881 | Tube OD, fin height, fin pitch per specification |
| Flattening & Flaring Tests | ASME SA179 | Verifies ductility and workability |
| Pull-Out Resistance | In-house per ASME guidelines | ≥ 70 N (fin tearing before detachment) |
| Material Traceability | Mill Test Certificates | Full chemical and mechanical certification |
Finned tube bundles with ASME SA179 base tubes and Al1060 G-type fins are specified for air-cooled heat exchanger service across multiple industries:
G-type embedded fins expand the effective heat transfer area by 5-8× compared to bare tubes. The mechanical embedding process ensures consistent fin-to-tube contact across the full operating temperature range, maintaining thermal efficiency without the degradation seen in adhesive-bonded or welded fin designs.
A: The maximum continuous fin base temperature is approximately 285°C (545°F). The G-type embedded design allows tube wall temperatures up to 400°C, but the aluminum fin material limits the fin tip temperature to avoid softening.
A: G-type (embedded) fins offer superior mechanical retention and thermal contact at elevated temperatures compared to L-type (wrapped) fins. Extruded fins provide the highest mechanical bond but are typically limited to aluminum base tubes. G-type is the preferred choice for carbon steel tubes in high-temperature air cooler applications.
A: Yes. Replacement bundles are fabricated to match existing header dimensions, tube layout, and overall envelope, allowing drop-in replacement without structural modifications.
A: Standard NDT includes eddy current testing of each tube, hydrostatic testing of the assembled bundle, and dimensional verification. Additional testing (radiographic, ultrasonic) can be specified per project requirements.
For project-specific engineering support, material certifications, or custom bundle designs, contact the Yuhong Group sales team: vladimir@steelseamlesspipe.com
