Integrally Finned Tube
Developed as a method of increasing heat transfer performance of fluids whilst minimising the physical size and cost of the heat exchanger
The fin is produced by being rolled from the wall of the tube and is therefore integral with the tube itself. Due to fin rolling the wall thickness beneath the fin section is reduced compared with the plain ends. The bore of the fin section is slightly reduced. Most tubular materials can be finned, however hardness of the material usually determines the finning code or fin profile.
Harder materials such as stainless steel, nickel alloys and titanium are usually supplied with a greater fin density (28, 30 or 36 fins / inch). This shallower fin profile reduces work hardening of the material and helps eliminate the possibilty of fin root cracking. Softer materials such as carbon steel, copper and copper alloys are usually supplied with a deeper profile giving a lower fin density (16 or 19 fins / inch).
Plain ends and any skipped sections must be specified.
Finished tubes can be U bent if required. The U bend area can be either finned or plain, to meet the required specification.
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Manufacturing Limitations
Materials:
1. Carbon and low alloy steel
2. Stainless steel: TP304 / TP304L / TP316 / TP316L
TP321 and duplex
3. Copper alloys: Alloy 443 / 687 / 706 / 715 etc
4. Titanium and high nickel alloys Tube Sizes
outside diameter: 12.7 / 15.8 / 19.05 and 25.4mm
Plain end wall thickness: >= 1.25mm
Length: up to 24,000mm
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Surface Area Improvement
Typical surface area improvements by using integral
low finned tubes are:
1. 19.05mm OD with 19 fins / inch: 270%
2. 25.4mm OD with 26 fins / inch: 330%
Depending on the fluids within the heat exchanger the
thermal improvement can range from between 20%
to in excess of 100%
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Alloy
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Plain Dimensions
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Finned Dimensions
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Outside
Diameter
(mm)
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Wall
Thickness
(mm)
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FPl
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Fin OD
(mm)
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Fin
Height
(mm)
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Notch of Fin
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Nominal Outside Surface Area(㎡/m)
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Actual Outside Surface Area(㎡/m)
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Wall
Under
Fins
(mm)
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Ridge Number
(n)
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Ridge Height
(mm)
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Nominal Outside Surface Area
(㎡/m)
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Actual Outside Surface Area(㎡/m)
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T2/TP2
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16
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1.10
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42
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15.85
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0.90
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√
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0.050
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0.203
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0.65
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--
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--
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0.040
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0.040
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16
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1.20
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42
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15.85
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0.90
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√
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0.050
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0.211
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0.63
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30
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0.30
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0.040
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0.048
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15.88
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1.00
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46
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15.80
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0.75
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√
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0.050
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0.195
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0.60
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20
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0.35
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0.041
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0.048
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19
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1.13
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46
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18.85
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0.95
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√
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0.060
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0.272
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0.63
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45
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0.38
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0.050
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0.084
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19
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1.20
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46
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18.85
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0.95
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√
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0.060
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0.272
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0.65
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45
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0.38
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0.049
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0.084
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19
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1.13
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50
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18.85
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0.92
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√
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0.060
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0.288
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0.63
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45
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0.38
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0.050
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0.084
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25.25
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1.18
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50
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25.25
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0.92
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√
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0.060
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0.391
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0.71
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54
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0.40
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0.069
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0.118
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BFe10-1-1
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18.85
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1.20
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46
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18.85
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0.90
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√
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0.060
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0.263
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0.71
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--
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--
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0.049
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0.049
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HSn70-1
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18.85
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1.20
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46
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18.85
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0.85
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√
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0.060
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0.253
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0.71
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3.3
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0.25
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0.050
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0.060
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HAl77-2
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13.85
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1.50
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42
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13.85
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1.0
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√
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0.044
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0.191
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1.1
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--
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--
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0.030
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0.030
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Monometallic finned tube with fins drawn from the parent metal of the tube. All monometallic Tubes are using a cold rolling or ribbing process.
Materials: Aluminium, copper, brass, cupronickel, carbon steel, stainless steel, titanium, etc.
FPI: 12, 16, 19, 28, etc.
OD: 1/2"-1"
Applications:
Aftercoolers, air coolers, air heaters, charge air chillers, condensers, convection heaters, electric heaters, evaporators, fluid coolers, gas coolers, heat pipes, hydrogen coolers, industrial tumble dryers, intercoolers, immersion heaters, oil coolers, radiators, refrigeration, solvent recovery and steam to air heat exchangers.
Benefits of Finned tubes
Finned tubes provides 2.5 to 3 times the external surface area of bare tube, which yields numerous benefits for the heat transfer equipment. Reduced pace, weight & structural savings in compact heat exchanger is valuable. The more expensive the tube material, the more dramatic the cost savings for corrosive service. Proper material selection can eliminate costly downtime & maintenance. Coastal refineries using once-through seawater cooling systems can benefit by substituting conventional copper nickel tubing with Titanium finned tube, Titanium finned tube is highly resistant to seawater corrosion erosion.
Quality standards:
ASME Sec. 8, Div 1, UG-8 (and Appendix 23 for external pressure rating where necessary)
ASTM B-891 Seamless and Welded Titanium and Titanium Alloy Condenser and Heat Exchanger Tubes with Integral Fins
ASTM A-1012 Seamless and Welded Ferritic, Austenitic and Duplex Alloy Steel Condenser and Heat Exchanger Tubes with Integral Fins
ASTM A-498 Seamless and Welded Carbon, Ferritics and Austenitic Alloy Steel Heat Exchanger Tubes with Integral Fins
ASTM B-359 Copper and Copper Alloy Seamless Condenser and Heat Exchanger Tubes with Integral Fins
