ASTM A213 T9 Studded Alloy Steel Seamless Tube For Air Heaters And Economizers

Key Features of ASTM A213 T9 Studded Tube

1. Material Composition

• Grade T9 is a low-alloy steel containing ~9% chromium and ~1% molybdenum, providing improved oxidation and corrosion resistance at elevated temperatures compared to carbon steel.
• Conforms to ASTM A213, which covers seamless ferritic and austenitic steel boiler, superheater, and heat-exchanger tubes.

2. Studded Design

• Studs (pins or projections) are resistance-welded to the tube's outer surface to improve heat transfer in gas-to-liquid or gas-to-steam applications.
• Common stud materials include carbon steel, stainless steel, or alloy steel depending on service conditions.

3. Standards & Specifications

• ASTM A213: Covers seamless tubes for high-temperature service.
• ASME SA213: Equivalent ASME Boiler and Pressure Vessel Code version.
• Stud welding standards: Typically follows AWS C1.1 for resistance welding.

4. Benefits of Studded Tubes

• Enhanced heat transfer due to increased surface area.
• Reduced fouling & improved gas flow in flue gas applications.
• Better durability in high-temperature corrosive environments.

5. Manufacturing & Testing

• Seamless tube fabrication (mandrel-rolled or extruded).
• Stud welding performed under controlled conditions.
• Nondestructive testing (NDT) such as hydrostatic, ultrasonic, or eddy current testing.
• Chemical & mechanical testing per ASTM A213 requirements.

ASTM A213 T9 Studded Tube Application

The ASTM A213 T9 studded tube is specifically designed for high-temperature, high-pressure environments where enhanced heat transfer and resistance to oxidation/corrosion are critical. Below are some key applications where this tube excels:

1. Waste Heat Recovery Boilers (WHRB)

• Used in HRSGs (Heat Recovery Steam Generators) in power plants and refineries to recover heat from exhaust gases (e.g., gas turbine flue gas).

Why T9?

• Resists sulfidation & oxidation in flue gas environments (up to ~1,100°F / 593°C).
• Studs increase heat absorption efficiency from hot gases.

2. Coal-Fired & Biomass Boilers

• Convection pass & economizer sections where flue gas temperatures are high (~800–1,200°F / 427–649°C).

Why Studded?

• Prevents ash fouling by disrupting gas flow.
• Improves heat pickup in low-temperature zones.

3. Fluidized Bed Boilers (CFB & BFB)

• Used in circulating fluidized bed (CFB) and bubbling fluidized bed (BFB) boilers.

Why T9?

• Resists erosion-corrosion from abrasive bed materials.
• Molybdenum content helps with creep resistance under cyclic loads.

4. Refinery & Petrochemical Heaters

• Fired heater convection sections (e.g., crude oil heaters, reformer furnaces).

Why Studded Tubes?

• Maximizes heat recovery from hot combustion gases.
• Reduces hot spots by improving heat distribution.

5. Air Heaters & Economizers

• Regenerative/recuperative air heaters in power plants.

Why T9?

• Handles sulfur-bearing flue gases better than carbon steel.
• Studs prevent fly ash buildup and improve thermal efficiency.

Air Heaters Alloy Steel Seamless Tube

Economizers Alloy Steel Seamless Tube

Studded Alloy Steel Seamless Tube

ASTM A213 T9 Studded Alloy Steel Seamless Tube For Air Heaters And Economizers Images