ASTM A312 TP304L Studded Tube with 11Cr Stud Fins for Oil and Gas
Industry
The ASTM A312 TP304L Studded Tube with 11Cr Stud Fins is a
specialized type of heat exchanger tube designed for enhanced heat
transfer in high-temperature and corrosive environments. Here's a
detailed breakdown:
1. Base Tube Material: ASTM A312 TP304
(1) Chemical Composition (Weight %)
The composition of ASTM A312 TP304L (UNS S30403) per ASTM
A312/A312M and ASTM A999/A999M (for general requirements) is as
follows:
| Element | Composition (%) |
| Carbon (C) | ≤ 0.03 (max) |
| Manganese (Mn) | ≤ 2.00 (max) |
| Phosphorus (P) | ≤ 0.045 (max) |
| Sulfur (S) | ≤ 0.030 (max) |
| Silicon (Si) | ≤ 1.00 (max) |
| Chromium (Cr) | 18.00 – 20.00 |
| Nickel (Ni) | 8.00 – 12.00 |
| Nitrogen (N) | ≤ 0.10 (max) |
| Iron (Fe) | Balance |
Key Notes:
Low Carbon (≤0.03%) prevents carbide precipitation during welding
(sensitization resistance).
Higher Chromium (18-20%) & Nickel (8-12%) provide excellent
corrosion resistance (especially against acids and chlorides).
Nitrogen (≤0.10%) may be added for strength stabilization.
(2). Mechanical Properties
Per ASTM A312, the mechanical properties of TP304L in the annealed
condition are:
| Property | Value |
| Tensile Strength (min) | 485 MPa (70 ksi) |
| Yield Strength (0.2% offset, min) | 170 MPa (25 ksi) |
| Elongation (min, % in 2" or 50mm) | 35% |
| Hardness (max) | 192 HB (Brinell), 90 HRB (Rockwell B) |
Additional Notes:
Ductility: High elongation (≥35%) ensures good formability and
weldability.
Hardness Limit: Keeps the material soft enough for machining and
welding.
Temperature Resistance: Suitable for cryogenic to ~800°F (~425°C)
continuous service.
2. Studded Tube with 11Cr Stud Fins
Stud Fins: Small cylindrical or conical projections welded onto the tube's
outer surface to increase surface area.
Material (11Cr Studs):
Likely refers to 11% Chromium steel (similar to Grade 11 in ASTM
A182, a ferritic/martensitic stainless steel).
Offers good heat resistance, moderate corrosion resistance, and
high strength at elevated temperatures.
Purpose:
Enhances heat transfer efficiency in boilers, heaters, and waste
heat recovery systems.
Improves turbulence, reducing fouling and improving thermal
performance.
3.Key Advantages
- Corrosion Resistance: TP304L base resists oxidation and chemical
attack.
- High-Temperature Performance: 11Cr studs withstand thermal cycling.
- Efficiency: Stud fins boost heat transfer without significantly
increasing pressure drop.
The ASTM A312 TP304L Studded Tube with 11Cr Stud Fins is designed
for high-efficiency heat transfer in demanding environments where
corrosion resistance, thermal performance, and mechanical
durability are critical. Below are its key applications, along with
the reasons why this specific combination (TP304L tube + 11Cr
studs) is used:
Primary Applications of ASTM A312 TP304L Studded Tube with 11Cr
Stud Fins
(A) Waste Heat Recovery Systems
Used in: Boilers, economizers, air preheaters, and heat recovery
steam generators (HRSGs).
Why?
The TP304L base tube resists corrosion from flue gases,
condensates, and acidic byproducts.
11Cr (chromium steel) studs withstand high temperatures (up to
~650°C) and improve heat absorption from exhaust gases.
(B) Power Plants & Boilers
Used in: Superheaters, evaporators, and feedwater heaters.
Why?
TP304L handles steam and high-pressure water without corrosion.
Stud fins increase turbulence and heat transfer rates, improving
efficiency.
(C) Petrochemical & Refining
Used in: Crackers, reformers, and process heaters.
Why?
Resists sulfur compounds, chlorides, and acidic fluids (TP304L).
11Cr studs provide mechanical strength in coking/fouling-prone
areas.
(D) Chemical Processing
Used in: Reactor jackets, condensers, and acid-cooling systems.
Why?
TP304L is ideal for nitric acid, organic acids, and alkaline
solutions.
Studs prevent fouling in viscous or particulate-laden fluids.
(E) Renewable Energy (Biomass/Waste-to-Energy)
Used in: Biomass boilers, incinerators, and syngas coolers.
Why?
TP304L resists chloride-induced stress corrosion cracking (common
in waste fuels).
11Cr studs endure abrasive ash and thermal cycling.
