Product Description Content
API 661 Air Cooled Finned Tube Bundles & Thermal Equipment Replacement Cores
Yuhong Group Co., Ltd. is an integrated manufacturer of high-performance thermal heat transfer equipment, pressure vessels, and precision replacement cores. We engineer and fabricate custom finned tube bundle units for air-cooled heat exchangers (ACHE), forced/induced draft air coolers, standard shell and tube heat exchanger units, and heavy forged heat exchanger tubesheet assemblies serving the global oil & gas and petrochemical processing sectors.
By integrating seamless tube production with structural bundle assembly, Yuhong Group provides full metallurgical traceability and dimensional accuracy. In addition to specialized air cooler replacement cores, our engineering capabilities include traditional u tube bundle structures and full-scale shell & tube heat exchanger vessels manufactured in compliance with API 661, ASME Section VIII Division 1, and ISO 13706 standards.
Finned Tube Bundle Configurations & Construction Types
We engineer forced-draft and induced-draft finned tube bundle replacement modules tailored to specific operating pressures, fluid corrosivity, and ambient thermal conditions:
Extruded Fin Tubes (Type KL / Extruded Aluminum): Base tube enclosed within a outer aluminum sleeve, roll-formed to create integral fins. Offers continuous metallic contact, protecting the base tube bundle from atmospheric corrosion up to 300°C.
Embedded Fin Tubes (Type G / High-Tension Embedded): Helical fins wound under tension into a CNC-machined groove on the base tube outer surface. Suitable for continuous operating temperatures up to 400°C in high-heat refinery streams.
L-Foot / Double L-Foot Fin Tubes (Type L / LL): Helical aluminum tape formed into an L-shape and wrapped under tension around the base tube wall, providing cost-effective thermal efficiency for ambient air cooling duties up to 130°C.
Plug Header Box Bundles (API 661 Standard): Features welded rectangular header boxes with threaded shoulder plugs aligned opposite each tube end, facilitating individual tube mechanical cleaning, inspection, and maintenance.
Removable Cover Plate / Bonnet Headers: Designed for low-pressure, severe fouling media, allowing complete removal of the header cover plate for rapid hydro-blasting without dismantling pipework.
Header Box & Finned Bundle Component Specifications
| Component | Manufacturing Standards & Materials | Technical Role in Air Cooled Exchangers |
| Plug Header Box | Heavy Forged Carbon Steel (SA516 Gr 70) or Stainless Steel (316L/Duplex 2205) | Serves as the high-pressure fluid distribution manifold; equipped with threaded inspection plugs for maintenance access. |
| Finned Heat Transfer Tube | Carbon Steel, Stainless Steel, or Alloy Base Tube with Extruded/Embedded Aluminum Fins | Forms the primary heat transfer boundary; extended aluminum surface area increases air-side thermal efficiency. |
| Tube Sheet / Tube Hole Plates | Heavy Forged Plate, Precision CNC Drilled with Serrated Groove Pattern | Functions as the primary pressure containment wall between process fluid and ambient air while holding tube ends. |
| Threaded Plugs & Gaskets | Carbon Steel / Alloy Plugs with Precision Soft Iron or Stainless Steel Gaskets | Seals header inspection holes opposite tube ends; engineered to sustain high-pressure cycling without leakage. |
| Side Frames & Tube Supports | Heavy Structural C-Channels with Vibration-Damping Aluminum / Zinc Tube Spacers | Supports total bundle weight, prevents sag across long tube spans (up to 12m), and isolates tubes against wind-induced vibration. |
Technical Highlights & Manufacturing Rigor
Precision Tube-to-Tubesheet Expansion: Automated torque-controlled hydraulic expansion into double-grooved tubesheet holes ensures mechanical joint tightness under working pressures up to 35 MPa.
Vibration-Resistant Framing: Engineered structural side channels and vibration-damping spacers prevent flow-induced tube fluttering and fretting damage caused by high-velocity forced draft fan air streams.
Controlled Welding Integrity: Header box pressure seams undergo full-penetration submerged arc welding (SAW) or orbital TIG welding, followed by 100% Non-Destructive Examination (NDE).
Comprehensive Quality Protocols: Each finned tube bundle undergoes Hydrostatic Pressure Testing (up to 1.5x design pressure), Air-Under-Water Leak Testing, Pneumatic Testing on header welds, and Positive Material Identification (PMI).
Engineering Guidelines: Air Cooler Sizing & Maintenance Protocols
Air-Side Fouling & Fin Cleaning: Dust, particulate, and insects accumulating on external fin surfaces increase air-side pressure drop and reduce thermal exchange efficiency. Specifying extruded fin geometries (Type KL) allows safe cleaning via high-pressure water washing or steam jetting without flattening fin structures.
Managing Winterization & Fluid Freezing: In cold-climate gas processing plants, low ambient air temperatures can freeze stagnant process fluids within outer tube rows. Integrating recirculation louvers, variable pitch fans, or internal steam coils maintains process fluid temperature above freezing thresholds.
Plug Leakage Prevention: During maintenance turnarounds, threaded header plugs must be cleaned and fitted with new soft-metal gaskets (such as soft iron or SS316). Torque wrench tightening according to API 661 torque patterns prevents thread galling and header weeping upon unit restart.
Target Industries & Primary Applications
Oil & Gas Production: Natural gas compressor intercoolers/aftercoolers, LPG recovery units, and offshore platform gas cooling modules.
Petroleum Refining: Crude Distillation Unit (CDU) overhead condensers, hydrotreater effluent coolers, and vacuum residue air coolers.
Petrochemical Processing: Ethylene oxide/glycol coolers, aromatics plant condenser banks, and ammonia loop air coolers.
Power Generation: Steam turbine surface condensers, turbine lube oil air coolers, and generator closed-loop cooling circuits.
Contact Yuhong Group Engineering Team
Contact our engineering sales department to request quotes or technical assistance for custom finned tube bundle modules, replacement tube bundle assemblies, complete shell and tube heat exchanger units, or precision heat exchanger tubesheet fabrications:
Company: Yuhong Group Co., Ltd.
Website: www.tema-heatexchanger.com
Direct Email: jimmy@steelseamlesspipe.com
Design Standards: API 661, ISO 13706, ASME Section VIII Div 1, TEMA Class R/B/C, PED 2014/68/EU
