Alloy Engineering Blog

Advantages Of Wrought Radiant Tubes vs. Cast Tubes

Achieving maximum production efficiency in manufacturing is never a ‘done deal’. Competitive pressures and rising costs continually challenge us to find or create ways to raise the bar and achieve greater productivity. Every process and component should be under constant evaluation for improvement. Furnace designers and maintenance personnel are always striving for better efficiencies to increase furnace uptime.

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Today, most often,  wrought radiant tubes are the best solution in most applications. They can be fabricated in any configuration or wall thickness, and support virtually all furnace OEM tube designs without any pattern charges. However, some customers still prefer cast tubes over fabricated because of their creep strength; certain shapes that cannot be fabricated economically from available wrought product forms; and since casts parts avoid most fabrication techniques, the price per pound of a fixture could be lower.

Wrought materials are free of external and internal defects that might be present in cast tubes. They’re more stable and much easier to weld repair in comparison to an embrittled cast tube, too. Also, wrought tubes return bends, flanges, bungs, and straight components can be repaired or replaced on site. This can be a great time saver.

Alloy Engineering can provide both wrought and cast tubes, but the higher weight (and cost) coupled with longer lead times makes cast tubes less appropriate in most applications. Tubes fabricated from ductile high-nickel, low-carbon alloys (with a controlled, tight grain structure) have high resistance to thermal fatigue. Fabricated tubes can be made in thinner sections that reduce the amount of internal thermal stresses within the material itself. This allows for inherently greater ductility in wrought materials that promote better resistance to thermal cycling and thermal shock.

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Achieving maximum production efficiency in manufacturing is never a ‘done deal’. Competitive pressures and rising costs continually challenge us to find or create ways to raise the bar and achieve greater productivity. Every process and component should be under constant evaluation for improvement. Furnace designers and maintenance personnel are always striving for better efficiencies to increase furnace up time. time.

Timely replacement of radiant tubes and other furnace components for many types of metal processing can make a difference in productivity and uptime. Alloy Engineering’s logistics-support program includes stocking replacement components, and eliminating costly supply and inventory hassles. AECo proactively evaluates the needs of our customers, in order to anticipate on-going replacement needs. The key to successfully managing needs is continual communication and assessment of product performance to stay ahead of the game.

Understanding what causes a tube to fail is important. Often, deformities can occur in the tubes themselves from many variables such as how they are supported, the amount of thermal cycling imposed, and the lack of room for expansion. Metal dusting in the tubes can slowly cause oxidization and failure. In some cases, improper joint fusion or joint prep can cause failure in a wrought or cast tube. AECo is diligent about properly preparing the areas to be welded, in order to minimize the risk of failure and maximize the potential lifetime of the unit.

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The key is to evaluate and understand each application and the environment in which the units are operating, in order to make the best decisions for each.

As far as supply and response times, AECo encourages on-going dialogue with our sales engineers and applications specialists to determine the best way to manage needs and respond in emergency situations. In most applications, just-in-time (JIT) delivery arrangements can be established to eliminate fabrication and component-acquisition delays entirely.