Product Description
Introduction of LL Type Finned Tube for Heat Exchanger
Type LL finned tube is a finned tube in which the fin feet are preformed into an LL shape (overlapping LLs) and a strip of aluminum fins or copper fins is applied to the base tube under tension. However, the feet are pre-formed so that one foot overlaps the other, increasing the base tube protection and thermal contact area of the finned tube. LL Type Finned Tube is usually used in steam coils, air pre-heaters., the maximum operating temperature can reach 180 °C.
The "LL" shaped fin design features interlocking fins that are twisted together to prevent movement and separation. The fins protect the entire tube, the smooth flat fins with "LL" shaped fins perpendicular to the surface of the seamless steel tube tube provide very low resistance to air/gas flow and ensure that fouling is kept to a minimum. The bottom of the fin is in contact with the base tube and provides a complete jacket over the length of the fin. Hence the name applies to applications where corrosion is a factor. This LL Type Finned Tube is often used as a replacement for more expensive extruded fins in corrosive environments.
LL Type Finned Tube for Heat Exchanger Quick Details:
Core tube material:
1. Carbon steel: A179, A192, SA210 Gr A1/C, A106 Gr B
2. Stainless steel: TP304/304L, TP316/TP316L
3. Copper: UNS12200/UNS14200/UNS70600, CuNi70/30, CuNi 90/10
4. Titanium: B338 Gr 2
Fin material:
1. Aluminum (Alu.1100, Alu.1060)
2. Copper.
3. Steel
Fin type: Solid plain
Fin Tube Type:LL Type
Outer diameter (OD): 16mm Min~50.8mm max.
Tube length: up to 18,000 mm.
Fin height: 16.5mm max.
Fin thickness: generally 0.4mm~0.6mm
Fin pitch: 2.1mm minimum (12FPI)
Surface Protection: Both bare ends shall be zinc or aluminum metallized by electrospray arc system coating.
Accessories: Tube support boxes, clamps or spacer boxes (materials: aluminium, zinc and stainless steel).
Additional Info
Payment Terms:T/T, LC
Delivery: 15-30 days after payment
Marking: Standard + Steel Grade + Size + Heat No + Lot No
Package: Iron frame packing boxes and the desiccants are put into each package for continental transportation as well. or as required
The case of "LL" type tension winding type.
Common Specifications of L Type Finned Tube for Heat Exchanger
| All dimensions are in Inches and specification upon your requests |
| Tube OD |
Fin Height |
Fin Thickness |
Fins per Pitch |
| 5/8 |
3/8,1/2 |
.015/.016/ .020 |
6, 7, 8, 9, 10, 11, 12 |
| 3/4 |
5/8,1/2 |
.015/.016/ .020 |
6, 7, 8, 9, 10, 11, 12 |
| 1 |
5/8,1/2 |
.015/.016/ .020 |
6, 7, 8, 9, 10, 11, 12 |
| 1 1/4 |
5/8,1/2 |
.015/.016/ .020 |
6, 7, 8, 9, 10, 11, 12 |
| 1 1/2 |
5/8,1/2 |
.015/.016/ .020 |
6, 7, 8, 9, 10, 11, 12 |
We can customize L Type Finned Tube for heat exchanger according to your drawings
Example:
Manufacturing Process:
Type LL finned tubes are preformed into LL shape (overlapping LLs) with fin feet and aluminum fin tape or copper fin tape is applied to the base tube under tension. The feet are pre-formed to allow one foot to overlap the other, increasing base tube protection and finned tube thermal contact area.
LL Finned Tube is combined with two different materials
Core tube material: carbon steel, low alloy steel, stainless steel, brass, copper, copper-nickel alloy, aluminum bronze, nickel alloy.
| Core Tube Material |
| Carbon Steel Tubes |
A179, A192, SA210 Gr A1/C, A106 Gr B, A333 Gr3 Gr6 Gr8, A334 Gr3 Gr6 Gr8, 09CrCuSb, DIN 17175 St35.8 St45.8, EN 10216 P195 P235 P265, GB/T3087 Gr10 Gr20, GB/T5310 20G 20MnG, |
| Alloy Steel Tubes |
A209 T1 T1a,A213 T2 T5 T9 T11 T12 T22 T91,A335 P2 P5 P9 P11 P12 P22 P91,EN 10216-2 13CrMo4-5 10CrMo9-10 15NiCuMoNb5-6-4 |
| Stainless Steel Tubes |
TP304/304L, TP316/TP316L TP310/310S TP347/TP347H |
| Copper Tubes |
UNS12200/UNS14200/UNS70600, CuNi70/30, CuNi 90/10 |
| Titanium Tubes |
B338 Gr 2 |
Fin material: aluminum, copper, steel
1. Aluminum (Alu.1100, Alu.1060)
2. Copper.
3. Steel
Quality Control for LL Type Finned Tube for Heat Exchanger
Inspection and Tests Performed
Chemical Composition inspection,
Mechanical Properties Test(Tensile Strength, Yield Strength, Elongation, Flaring, Flattening, Hardness, Impact Test), S
surface and Dimension Test,
No-destructive Test,
Hydrostatic Test.
Delivery condition:
Tube ends are square cut, free burrs, internally dried and air blown clean, externally coated with varnish at both ends of G-Fin Embedded Finned Tube.
Acceptance Criteria
API Standard 661 (Air-Cooled Heat Exchangers for General Refinery Service) or Delivery Conditions (TDC).
Features of LL Type Finned Tube for Heat Exchanger
1. High heat transfer performance and small contact thermal resistance.
2. The contact area between the fin and the tube is large, and the fit is tight and reliable.
3. Good resistance to atmospheric corrosion and stable long-term use
4. Can be used for a long time at high temperature
Application of LL Type Finned Tube for Heat Exchanger
Petroleum, chemical and petrochemical industries
Natural gas treatment
Steel industry: blast furnace and converter system
Power generation: exhaust gas from steam turbine condenses, condensate water contact circulation cooling condensate, fossil and nuclear power plants
Air conditioning (Freon, ammonia, propane)
Waste incineration equipment
Compressor cooler, etc.
Maximum operating temperature of KL Type Finned Tube up to 400°C
Packaging picture of LL Type Finned Tube
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