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Internally-Finned Tubes


  • Reduction in Gas Consumption (~10%)
  • Increased Combustion Efficiency
  • Higher Operating Temperature to 2450°F (1340°C)
  • Longer Tube Life ( > 10 years)
  • Faster Recovery Rates & Increased Productivity

Finned Tubes Brochure


Unique Internal, Spiraled Fins

Our revolutionary Internally-Finned tubes not only deliver the same long life and superior heat transfer capability as our Straight-Wall tubes, but they literally pay for themselves. By simultaneously stirring the gas flame and increasing the inside surface area to capture more heat, these finned tubes reduce fuel consumption by approximately 10%.

Only INEX offers a radiant tube with internally-spiraled fins capable of operating at temperatures to 2450°F (1340°C).


Proven Cost Savings

INEX conducted a yearlong test in a pusher furnace. On a conservative basis, the results showed a 10.4% metered fuel savings. Rated at 600,000 BTUs per hour, the furnace was operated at high fire approximately 60% of the available time. A savings of over 300,000 cubic feet of gas resulted in an annual savings exceeding $1,220. Use your own figures and see the savings INEX Finned Tubes can deliver for you! 

For more information, please contact INEX with any questions via our Contact page.

Fin Tube Dimensions

U.S. Metric
Tube (OD)

Max Nozzle 

Fin Height Twist Rates
(per rev.)
Tube (OD) Max Nozzle Fin Height Twist Rates
(per rev.)
2 3/8"
(12 Fins)
1716" 1/4 inch 12 inches 60 mm 37 mm 6.4 mm 305 mm
2 3/4"
(18 Fins)
1916" 3/8 inch 18 inches 70 mm 40 mm 9.5 mm 457 mm
3 1/4" 
(15 Fins)
2⅜" 1/4 inch 12 inches 83 mm 60 mm 6.4 mm 305 mm
4 1/2"
(18 Fins)
3516" 5/16 inch 20 inches 114 mm 84 mm 7.9 mm 508 mm
Special fin heights and twist rates available upon request.
Note: Please call to discuss dimensional
capability for critical applications

  • Gaskets
  • Mounting Hardware (Bottom-Side Adaptor for replacing metal tubes)
  • Bellows (available for 2¾” & 3¼” OD Top-Side Sealing)
  • Packing Glands (Top-Side Sealing for 4½” OD tubes)