Stainless Steel G-Type Embedded Finned Tubes for Heat Exchangers
Material
This product is a G-type embedded finned tube, wherein fin strips are tension-wound and embedded into helically
machined grooves on the outer surface of the base tube, then
back-filled with the base-tube material to secure the fins.
For the “stainless steel version”, the base (core) tube is produced
from stainless steel (such as TP 304, TP 316, duplex stainless
steel, etc.), while the fin material may be aluminum, copper or
steel, depending on duty.
The embedded fin design offers enhanced heat-transfer surface area
and excellent mechanical bonding between fin and tube, reducing
contact thermal resistance and improving reliability in
high‐temperature, high‐velocity environments.
Specification
Typical specification for stainless steel G-type embedded finned tubes:
Base tube outer diameter (OD): ~ 16 mm up to ~ 51 mm (or larger on special order)
Base tube wall thickness: ~ 2.11 mm to 3.5 mm for G‐type fins
Fin height: up to ~ 17 mm in many cases
Fin thickness: typically ~ 0.4 mm to 0.6 mm
Fin pitch (spacing): e.g., ~ 2.1 mm minimum for some designs (≈12 FPI)
Tube lengths: up to ~18 000 mm (18 m) or more by special order
Material combinations: Tube: stainless steel (e.g., TP 304/304L, TP 316/316L, duplex S31803/S2205); Fin: aluminum 1100/1060, copper, steel
Surface protection: bare tube ends may be metallized (zinc or aluminum) or coated for corrosion resistance
Major Features
High heat transfer performance: The embedded fin design provides a large contact area between fin and tube, low thermal resistance and enhanced outer‐surface area for heat exchange.
Secure mechanical bond: Because the fin is embedded and back-filled, the fin-to-tube connection is very tight, resisting loosening or detachment under thermal cycling, vibration or high velocity air/gas flows.
Good corrosion and high-temperature resistance: Using stainless steel base tubes, the product supports long‐term use in corrosive or high‐temperature environments (depending on grade).
Customizable to duty: Fin height, pitch, thickness, tube diameter, material combinations may be tailored to specific heat‐exchanger duties (air-cooled exchangers, condensers, fin‐fan coolers, etc.).
Robust manufacturing and testing: Includes chemical composition analysis, mechanical properties (tensile, yield, elongation, hardness, flattening etc.), surface/dimension inspections, non‐destructive tests (NDT), hydrostatic tests.
Our Advantages
From a factory/manufacturer perspective, we address the key concerns that customers raise and offer solutions accordingly:
Fin‐to‐tube bonding integrity: Customers worry about fin strips detaching under thermal cycling, vibration or high‐velocity flows. Our embedded groove + back-fill process ensures a mechanically locked fin foot, maximizing contact area and finish flatness to achieve consistent fin adhesion.
Dimensional tolerance and straightness: Straightness of tube and fin alignment are critical for fin‐fan coolers and air‐cooled heat exchangers where vibration and air flow stress may occur. We control tube straightness to tight tolerances, inspect fin‐height and pitch in‐line, and ensure no burrs or fin foot protrusions.
Corrosion resistance and high‐temperature service: Especially for stainless steel tubes in petrochemical, power generation, waste‐incineration environments, we select appropriate stainless grades (TP 316/316L, duplex S31803 etc), ensure proper solution anneal and finish, and apply protective end coatings or metallizing where required.
Customization and batch consistency: We manufacture to API standards (such as API 661 for air-cooled exchangers) or customer’s TDC (technical delivery conditions), and document chemical/mechanical certificates for each lot.
Comprehensive testing and quality assurance: We perform full chemical analyses, mechanical tests, NDT (eddy current, visual, dimensional), hydrostatic pressure tests, and maintain traceability for each piece. Customers thus get documented assurance of performance and reliability.
Chemical Composition
Below is a comparative table of five relevant stainless grades commonly used for base tubes in the embedded finned tubes market, along with their typical chemical compositions (mass %) as per relevant standards:
| Grade | C | Si | Mn | P | S | Cr | Ni | Mo | Remarks |
|---|---|---|---|---|---|---|---|---|---|
| TP 304 | ≤0.08 | ≤1.00 | ≤2.00 | ≤0.045 | ≤0.030 | 18.0-20.0 | 8.0-11.0 | — | Common austenitic grade for general heat exchangers |
| TP 304L | ≤0.035 | ≤1.00 | ≤2.00 | ≤0.045 | ≤0.030 | 18.0-20.0 | 8.0-13.0 | — | Lower carbon for improved weldability |
| TP 316 | ≤0.08 | ≤1.00 | ≤2.00 | ≤0.045 | ≤0.030 | 16.0-18.0 | 10.0-14.0 | 2.0-3.0 | Molybdenum grade for corrosion resistance |
| TP 316L | ≤0.035 | ≤1.00 | ≤2.00 | ≤0.045 | ≤0.030 | 16.0-18.0 | 10.0-15.0 | 2.0-3.0 | Low carbon version for improved weld corrosion resistance |
| Duplex S31803 / S2205 | ≤0.03 | ≤1.00 | ≤2.00 | ≤0.04 | ≤0.015 | 22-24 | 4-6 | 3-3.5 | Duplex structure for high strength and corrosion resistance |
Mechanical Properties
Below is a comparative table of five relevant stainless grades and representative mechanical properties (room temperature, annealed/solution‐treated condition):
| Grade | Tensile Strength (Rm, MPa) | Yield Strength (0.2% Rp0.2, MPa) | Elongation (%) |
|---|---|---|---|
| TP 304 | ≥ 515 MPa | ≥ 205 MPa | ≥ 35 % |
| TP 304L | ≥ 485 MPa | ≥ 170 MPa | ≥ 35 % |
| TP 316 | ≥ 515 MPa | ≥ 205 MPa | ≥ 40 % |
| TP 316L | ≥ 485 MPa | ≥ 170 MPa | ≥ 35 % |
| Duplex S31803 / S2205 | 650-800 MPa | 450-550 MPa | 25-30 % |
Applicable Standards
ASTM A312 – Seamless and welded austenitic stainless steel pipes/tubes
API 661 – Air-Cooled Heat Exchangers for General Refinery Service
EN / GOST / JIS equivalents applicable upon request
Manufacturer or client TDC (Technical Delivery Conditions) may apply
Application Fields
Broad application domain
These stainless steel G-type embedded finned tubes are widely used in heat‐exchanger equipment where enhanced heat transfer from a tube to an outer gas or air stream is required, especially in corrosive, high temperature or high velocity environments. Example sectors: petrochemical plants, natural gas treatment, steel industry (blast-furnace, converter systems), power generation (thermal/nuclear), HVAC/air-conditioning, waste-incineration, compressor coolers, etc.
Specific usage in application domain
Petroleum / chemical / petrochemical industry: Embedded finned tubes serve in air-cooled condensers or coolers of process streams, where finned tube bundles allow compact design with high heat transfer efficiency.
Natural gas treatment: For gas coolers, waste-heat recovery, finned tubes handle large air volumes on the fin side and gas or fluid in the tube side.
Steel industry – blast furnace / converter systems: Exhaust gas cooling, dust removal and waste heat recovery often utilize finned tubes exposed to hot gases and vibration; embedded fins help ensure durability.
Power generation – steam turbine exhaust / condensers: Fin-fan coolers with embedded finned tubes condense steam or cool condensate water by air, requiring high surface area and corrosion resistance.
Air-conditioning / HVAC: Although many HVAC finned tubes are simpler, high performance embedded fin tubes may be applied in chillers, rooftop units or large scale air-cooled heat exchangers.
Waste incineration equipment / compressor coolers: Where hot air/gas streams and high velocities are present, the robust bonding of embedded fins helps ensure long-term service.
