ASTM A106 Gr.B Carbon Steel U Bend HFW Soild Fin Tube For Diesel Engine Exhaust Economizers

A106 Gr.B carbon steel U-bend finned tubes are highly efficient heat transfer elements. The base tube is made of ASTM A106 Grade B carbon steel. External fins are helically attached to the base tube to significantly increase its external surface area. High-frequency current generates skin and proximity effects, instantly generating high heat at the contact points between the base tube and the fin material, causing them to melt and fuse under pressure.

The finned tubes are bent into a tight "U" shape.

ASME SA / ASTM A106 GR.B Carbon Steel Seamless Pipes & Tubes Chemical Composition :

A 106 Grade B SMLS Pipes and Tubes Mechanical properties:

Soild

Process: The steel strip is fed into the high-frequency welding machine in a smooth state. Under high-frequency current and pressure, the smooth root of the strip melts and welds to the surface of the base tube instantly.

Advantages:

The process is mature, efficient, and the mainstream in the market.

Optimal thermal conductivity is achieved because the weld zone is continuous and complete.

Suitable for base tubes of various specifications, including thin-walled tubes.

Toothed

Punching: Uniform serrations are punched out at the root of the fin strip.

Grooving: Shallow spiral grooves are pre-rolled into the surface of the base tube.

Insertion and Welding: The toothed fin strip is wrapped and pressed into the grooves, causing the teeth to plastically deform and embed into the base tube. High-frequency welding is then performed. Welding occurs not only at the root of the fin, but also in the gaps between the teeth and the base tube.

Advantages:

Even if there are even tiny areas of incomplete welds, the mechanically interlocking teeth provide strong pull-out resistance, significantly reducing the risk of overall failure.

Excellent fatigue resistance: The mechanically interlocking structure effectively resists alternating thermal stresses caused by frequent starts and stops and sudden temperature fluctuations, preventing fatigue-induced cracking at the fin roots.

Application

Heat Recovery Steam Generators (HRSGs): Used in economizers or evaporator sections to recover heat from gas turbine exhaust.

Air Preheaters: Use hot flue gases to heat the boiler's combustion air.

Finned Tube Boilers: Used to generate the tubes within the boiler.

Process Gas Heaters/Coolers: Used in the petrochemical and refining industries.

Thermal oil heaters: Use thermal oil as the tube-side fluid to heat air or other gases.

Diesel engine exhaust economizers.