1. A335 P11 Base Tube Composition

2. A335 P11 Serrated Fin Tube Design

Structure:

Fins are mechanically attached or welded to the A335 P11 base tube in a helical pattern with periodic notches (serrations).

Serrations increase surface area by 8–10× compared to bare tubes and disrupt thermal boundary layers, enhancing turbulence.

Thermal Efficiency:

Serrations create micro-vortices, improving heat transfer rates by 25–40% over smooth fins.

Ideal for viscous fluids (e.g., heavy oils) or low-velocity gases where boundary layer resistance is high.

3. A335 P11 Serrated Fin Tube Manufacturing Process

Base Tube Production:

Seamless manufacturing via hot extrusion, cold drawing, or rotary piercing to ensure uniform wall thickness (2–130 mm).

Heat treatment (annealing or normalizing + tempering) optimizes grain structure.

Fin Attachment:

Extrusion: Aluminum fins cold-forged onto the tube, creating a metallurgical bond.

Welding: High-frequency welding for stainless steel fins; preheating (150–200°C) required for P11 to avoid cracking.

Quality Control:

Hydrostatic testing and non-destructive exams (e.g., eddy current) ensure leak resistance.

4. A335 P11 Serrated Fin Tube Key Applications

Power Plants:
Boiler superheaters/reheaters (e.g., SA-335 Gr.P11 tubes in coal-fired plants).

Petrochemical Industry:
Crackers, reformers, and heat recovery units handling corrosive gases (e.g., H₂S) at 400–550°C.

Enhanced Recovery Systems:
Waste heat boilers where serrated fins mitigate fouling from ash/particulates.

5. A335 P11 Serrated Fin Tube FAQ

1.What is the maximum service temperature for A335 P11 fin tubes?

• Up to 593°C (1,100°F) for continuous service. Above 480°C (900°F), its chromium-molybdenum alloy resists oxidation and creep deformation.

2.Why choose serrated fins over smooth fins?

• 25–40% higher heat transfer due to turbulent airflow from serrations.
• 30% less fouling (ash/soot buildup) in dirty gas applications.
• Ideal for viscous fluids or low-velocity gases (e.g., exhaust systems).

3. Can A335 P11 handle corrosive environments?

• Yes, but with limits:Excellent against steam oxidation and sulfur compounds (e.g., H₂S in refineries).
• Avoid chloride-rich environments (risk of stress corrosion cracking above 400°C).

4. How are fins attached to the base tube?

• Extrusion: Aluminum fins cold-forged onto the tube (metallurgical bond).
• Welding: Stainless steel fins welded using HF techniques (requires 150–200°C preheat for P11).

5. Where is it used most?

• Power plant boilers/superheaters (coal/gas-fired).
• Petrochemical crackers and heat recovery steam generators (HRSG).
• Waste heat boilers with high particulate loads.

Conclusion

A335 P11 serrated fin tubes combine the high-temperature resilience of chromium-molybdenum alloy with optimized heat transfer from serrated fin geometry. They are critical in energy-intensive sectors like power generation and petrochemical processing, where efficiency and material durability are paramount. For detailed specifications (e.g., dimensions: 21.3–762 mm OD; schedules: SCH20–XXS), refer to ASTM/ASME standards.

Yuhong Holding Group has more than 35 years experience for pipeline products, till now we have 3 big joint venture factories,  the total production area more than 130000 square meters, and more than 600 workers with 106 production lines give our clients excellent supporting always.   The factories already got certificates like : ABS, LR, DNV-GL, BV, KR, CCS, ASME, ISO 9001, ISO14001, ISO18001, ect.

Our factories main products as below : 
Factory 1th: Stainless steel seamless tube, Duplex steel seamless tube, Super duplex steel seamless tube, Nickel alloy steel seamless tube;

Factory 2th: Carbon steel seamless tube, Alloy steel seamless tube; Enhanced Heat Tranfer Tube, low fin tube ,U bending workshop;
Factory 3th: High frequency welding fin tube(HFW fin tube, Solid Fin tube, Studded Tube, Serrated Fin tube, Longitudinal welding fin tube), Wound fin tube(L type fin tube, LL type fin tube,  KL type fin tube), Embedded G type fin tube , Extruded fin tube,  low fin tube, U bend & 180deg. Return;

Yuhong Holding Group also has gained rich experience for project package( products contain:Pipes, Fittings, Flanges, heat exchanger, furnace, fired heater, air cooler, boiler) , YUHONG brand has marked its global presence in more than 85 countries, like, Korea, USA, Canada, Mexico, Colombia, Bolivia, Chile, Argentina, Brazil, Ecuador, Austria, New Zealand, Singapore, Malasyia, Indonesia, Thailand, Vietnam, Ukraine, Turkey,Sauid Arabia, Qatar, U.A.E,Israel,India, UK, France, Italy, Gernmany, Poland, Spain,... We have successfully implemented the orders of Cross Country Pipelines for our valuable customers. In addition, we have also developed a huge network of contacts and strategic alliances with most important manufacturers as stockists around the world.