Extruded Fintube

The extruded fin is formed from an outer aluminum tube with a large wall thickness (muff), which is aligned over an inner base tube. The two tubes are pushed through three arbors with rotating discs that literally squeeze or extrude the aluminum fins up and out of the muff material in a spiral shape in one operation. The resultant fin typically has a base or root thickness of .035", average fin thickness .016" and a tip of .009", with an overall height of 16mm (5/8"). The root thickness serves to form an uninterrupted bond over the entire tube length.

McElroy disc technology now makes it possible to fin thinner muff thus offering significant material savings. Recommended standard muff wall is .176" as opposed to industry practice of .183"-.210" In addition, the same growth factor can be used for pitches from 8 - 11 FPI, allowing for standardization on one muff thickness and eliminating the need to stock multiple muff wall thicknesses. The same discs can be used to produce 5/8" (15,9mm) or 1/2" (12,7 mm) high fin.

Model B produces a 5/8" high fin on tube sizes from 25mm to 1.5" ( 38.1mm). The Model B Extruded Finning Machine is now capable of 7/16" high integral copper fin at 7 to 10 FPI within the tube size range of the machine (25mm and 1.5"). Each machine is configured for the specific production requirements of the end user.

Service After Sales

  • Technical support
  • Training at your site or in McElroy's plant or both.
  • Periodic updates on the latest R&D
  • Information on maximum production criteria
  • Reference charts
  • Specifications for tube and fin stock

Machine Specifications

  • Length: 33.83 Meters (111 Feet)
  • Width: 9.4 Meters (30 Feet)
  • Typical tube length: 15.2 Meters (50 Feet) Extensions available for up to 18.3 Meters (60 foot tube). Other rack lengths are also available to accommodate customer's need.
  • Power Requirement: Customer will provide electrical power meeting the following specifications:
    • Supply Type: Three-phase TN-S, TN-C, TN-C-S, TT, or IT* supply with a 225A, fused disconnect conforming to local regulations.
    • Voltage: 460V ±5%
    • Frequency: 48Hz to 62Hz
  • Horsepower: 150 HP AC Motor
  • Isolation Transformer: 200 KVA; 50-60 Hz; Meets incoming plant voltage and steps up or down to provide 460V.
  • Manpower: One full-time operator, one disc stacker, and two helpers.

* Contact McElroy for additional requirements for an IT supply type.

Extruded Fin Specifications

  • Fin Material: Aluminum 1060-F; 1050-F; 6063-0. Physical properties can vary considerably and should be controlled. Suppliers should be given specific information to control OD and ID and to hold maximum yield to below 7500 PSI.
  • Max Fin Height: 5/8"
  • Linear Tube Material: No theoretical limits.
  • Production Rate: Production Rate 5/8 X 10 X 50': 885 feet per hour. Cruising RPM 2800, Max tube RPM 3600. (85% efficiency)
  • Type of Service: Generally used for more severe duties, especially if corrosion and thermal cycling is a problem.
  • Temperature: Typical Acceptable Tube Wall Operating Temperature
  • United States: 450° F (230° C) 
  • European: 480° F (250° C)
  • Advantages: Liner tube incased in aluminum for maximum corrosion protection.
  • Disadvantages: Use more material per foot of tube than W/O (58% more), OLFF (41% more), or Imbedded Fin (78% more).
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833 North Fulton, Tulsa, Oklahoma, 74115-6408 U.S.A.

(918) 831-9236

McElroy Manufacturing, Inc. © 2016