ASTM A312 TP304H Serrated Finned Tube With SS304H Fins For Heat
Recovery System
The ASTM A312 TP304H Serrated Finned Tube with SS304H Fins is a
high-performance heat exchanger component designed for demanding
industrial applications. Below is a detailed breakdown of its
composition, features, and advantages:
1. Base Tube Material: ASTM A312 TP304H
A high-carbon variant of 304 stainless steel (304H), offering
improved high-temperature strength and creep resistance.
Complies with ASTM A312, which covers seamless and welded
austenitic stainless steel pipes for high-temperature service.
Fins Material: SS304H (Stainless Steel 304H)
The fins are made of the same grade as the tube, ensuring
compatibility in thermal expansion and corrosion resistance.
Chemical Composition of ASTM A312 TP304H (Weight %)
| Element | ASTM A312 TP304H Requirements | Typical Values |
| Carbon (C) | 0.04–0.10% (min. for high-temp strength) | 0.06–0.08% |
| Manganese (Mn) | ≤2.00% | 1.20–1.50% |
| Silicon (Si) | ≤0.75% | 0.30–0.50% |
| Phosphorus (P) | ≤0.045% | 0.030–0.040% |
| Sulfur (S) | ≤0.030% | 0.015–0.020% |
| Chromium (Cr) | 18.0–20.0% | 18.5–19.5% |
| Nickel (Ni) | 8.0–11.0% | 8.5–10.5% |
| Iron (Fe) | Balance (~67–71%) | Balance |
| Nitrogen (N) | ≤0.10% | 0.05–0.08% |
Mechanical Properties of ASTM A312 TP304H (ASTM A312 Standard)
| Property | Requirements | Typical Values |
| Tensile Strength | ≥515 MPa (75 ksi) | 550–650 MPa |
| Yield Strength (0.2% Offset) | ≥205 MPa (30 ksi) | 220–310 MPa |
| Elongation (% in 50mm) | ≥35% | 40–50% |
| Hardness (Rockwell B) | ≤92 HRB | 70–85 HRB |
| Max. Operating Temperature | ~815°C (1500°F) | 650–815°C (for sustained loads) |
Comparison with Similar Materials
| Feature | TP304H Finned Tube | TP321/321H Finned Tube | TP316L Finned Tube |
| Max Temp. | ~815°C | ~900°C (stabilized) | ~450°C (lower C) |
| Corrosion Resistance | Good (oxidizing) | Better (acid/chloride) | Excellent (chlorides) |
| Cost | Moderate | Higher (Ti-stabilized) | Higher (Mo-added) |
2. Fin Type: Serrated (Indented or Cut Fins)
The fins have notches or serrations along their edges to enhance
turbulence and heat transfer efficiency.
3. Key Features & Benefits
a) High-Temperature Performance
TP304H has a higher carbon content (0.04–0.10%) than standard
304/304L, providing:
Better creep resistance (resists deformation under stress at high
temps).
Sustained strength up to ~815°C (1500°F).
Excellent oxidation resistance in steam and flue gas environments.
b) Enhanced Heat Transfer
Serrated fins create turbulence, improving heat exchange efficiency
by 20–30% compared to smooth fins.
Reduces fouling (deposits on the tube surface), making it ideal for
dirty or high-particulate gas streams.
c) Corrosion Resistance
SS304H offers strong resistance to:
Organic acids, chloride stress corrosion (in moderate conditions).
Oxidizing environments (e.g., nitric acid, steam).
Sulfur-bearing gases (common in oil & gas, petrochemicals).
d) Mechanical Strength
Tensile strength: ≥515 MPa | Yield strength: ≥205 MPa (per ASTM
A312).
Suitable for high-pressure applications (e.g., boilers,
superheaters).
4. Manufacturing Process
Seamless or welded tube made from TP304H stainless steel.
Fins are helically wound onto the tube and secured via
high-frequency welding or extrusion.
Serrations are cut or pressed into the fins post-attachment.
Dimensional inspection, hydrostatic testing, PMI (Positive Material
Identification).
The ASTM A312 TP304H serrated finned tube with SS304H fins is a
specialized heat exchanger component designed for high-temperature
and high-pressure applications. Here are its key applications:
1. High-Temperature Heat Exchangers
Used in boilers, superheaters, and reheaters in power plants.
Suitable for waste heat recovery systems in industries like steel,
cement, and petrochemicals.
2. Petrochemical & Refining Industries
Used in furnaces, reformers, and cracking units where corrosion
resistance and high-temperature strength are critical.
Handles aggressive fluids like hydrocarbons, sour gas, and acidic
environments.
3. Oil & Gas Processing
Applied in heat recovery steam generators (HRSGs) and gas coolers.
Resists sulfur corrosion (sour service) due to SS304H’s enhanced
chromium and nickel content.
4. Chemical Processing
Used in evaporators, condensers, and reactors handling corrosive
chemicals.
The serrated fins improve heat transfer efficiency in viscous or
fouling-prone fluids.
5. Power Generation (Coal, Gas, Nuclear)
Finned tubes enhance heat transfer in steam generation and exhaust
gas systems.
TP304H (high-carbon 304) offers better creep resistance at elevated
temperatures (up to ~815°C).
