Serrated finned tubes for Heat Recovery Steam Generators (HRSG) are high-efficiency heat transfer components designed for demanding high-temperature energy recovery systems. Manufactured with ASTM A335 P22 alloy steel seamless tubes as the base tube, these finned tubes provide enhanced heat transfer capability while maintaining excellent mechanical strength under elevated temperature and pressure conditions.

ASTM A335 P22 (also known as 2.25Cr-1Mo alloy steel) is widely used in power generation and industrial heat recovery equipment due to its good creep resistance, oxidation resistance, and thermal stability. Combined with a serrated fin structure, the tube surface area is increased while turbulence around the gas-side flow is improved, making it suitable for HRSG economizer, evaporator, and superheater sections.

The serrated fin design consists of interrupted fin segments instead of a continuous fin strip. The segmented structure helps:

• Increase gas-side turbulence
• Reduce boundary layer formation
• Improve heat exchange efficiency
• Maintain lower pressure drop compared with some high-density fin designs

This structure is commonly selected for HRSG applications where exhaust gas energy recovery efficiency is important.

The ASTM A335 P22 base tube provides:

• High-temperature mechanical strength
• Good resistance to thermal cycling
• Stable performance in steam and exhaust gas environments
• Suitable creep resistance for long-term operation

The material is commonly applied in components exposed to high-temperature flue gas and steam conditions.

Depending on project requirements, serrated finned tubes can be manufactured using:

• High frequency welded fins
• Spiral welded serrated fins
• Customized fin welding processes

The connection between fins and tube is designed to ensure efficient heat conduction and long-term operating stability.

ASTM A335 P22 serrated finned tubes are mainly used in:

Applications include:

• HRSG economizers
• HRSG evaporator tube bundles
• HRSG superheater sections
• Heat recovery modules for gas turbine exhaust systems

Used in:

• Combined cycle power plants
• Gas turbine waste heat recovery systems
• Thermal power auxiliary heat recovery equipment

Suitable for:

• Refinery waste heat recovery units
• Petrochemical process heat recovery
• Industrial exhaust gas boilers

Typical dimensions can be customized according to customer drawings and heat exchanger design requirements.

Material: ASTM A335 P22

Common outside diameter:

• 25.4 mm – 76.2 mm

Common wall thickness:

• 2.5 mm – 10mm

Common tube lengths:

• 3 m – 18 m

Common fin height:

• 10 mm – 25 mm

Common fin thickness:

• 0.5 mm – 1.5 mm

Common fin density:

• 5 – 15 fins/inch

Fin material options:

• Carbon steel
• Alloy steel
• Stainless steel
• Aluminum (according to operating temperature requirements)

Typical chemical composition requirements:

The chromium and molybdenum alloying elements improve high-temperature strength and corrosion resistance.

ASTM A335 P22 requirements:

Actual values depend on tube size, heat treatment, and manufacturing conditions.