Parallel Finned Tubes|Rectangular Finned

What is Parallel Finned Tubes?

Parallel Finned tubes are made of welded square fins. It also called H type finned tubes. Parallel finned tubes can be double tube or single tubes. Parallel finned tubes fabricate by resistance welding the fins on tubes.

Parallel finned tubes applications:

Parallel finned tubes are largely integrated for typical applications with waste heat recovery boilers and economizers running with coal, heavy fuel oil, industrial waste or domestic refuses burning .

Parallel finned tubes allows the use in all conventional cleaning systems : shot blasting, air or steam blowing, washing…

The ’Double H’ design to weld double tubes with the steel fins at the same time. This configuration can reduce the number of supports required due to its inherent stiffness.

Parallel finned tubes advantage, 

The alignment of the fins in the bundle allows the creation of self cleaning parallel channels, with low pressure drops.

Parallel finned tubes Focus

Fin pitch from 10 to 30 mm.

Tube length up to 15 meters.

Fin interruptions can be on request.

Parallel finned tubes material:

Base material for tube and fins : carbon steel A179， A192, Alloy Steel as per A213 A335, Stainless steel A312, Compatible with cast iron finned tubes for hybrid units. Special fin dimensions on request.

According to the requirements of the domestic market, after years of experience and learning from advanced countries, our company has upgraded the H-type finned tube/Parallel finned tubes welding equipment, which has a high degree of automation. The welding technology and product quality have reached the certification of the International Classification Society and other authoritative certification bodies.

1. H-type finned tube/Parallel finned tubes Welding strength and stability

1.1 Pull off force test: greater than 200MPa or partial tear of steel pipe

1.2 Weld width: greater than fin thickness, i.e. welding rate>99%

1.3 Stability of welding strength: the first piece of each shift shall be welded to meet the requirements of 2.1 or 2.2

1.4 Weld bending resistance test: the fins are bent 20 degrees left and right, bent left and right twice, and the weld is free of cracks

1.5 Hammer test: strike the upper part of the fin parallel to the steel pipe until the fin falls off, and the fin itself shall not break

1.6 If the test fails, the annealing function must be enabled

2. H-type finned tube/Parallel finned tubes heat affected zone

Measurement with microscope and microhardness tester

The depth of heat affected zone of steel pipe is less than 0.5mm

3. H-type finned tube/Parallel finned tubes dimensional accuracy

3.1 Overall length of wing segment – 1mm~+1mm segmental motion accuracy – 0.5mm~+0.5mm

3.2 Spacing – 0.2mm~+0.2mm

3.3 Verticality of fins and steel pipes – 1 °~+1 °

3.4 The flatness of butt welded fins in the same group is – 0.2mm~+0.2mm, except for the height difference caused by the thickness tolerance of fins

3.5 Height difference of butt welded fins in the same group – 0.2mm~+0.2mm

3.6 Tolerance of double pipe center distance – 0.5mm~+0.5mm

3.7 Under the conditions of the same steel pipe material, the same sheet spacing and sheet number, the length change of different finned tubes after welding is consistent

4. H-type finned tube/Parallel finned tubes welding speed

Base tube outer diameter 25~51, fin thickness 2mm, each pair of welding time less than 3s (excluding feeding and unloading time and annealing time)