For international market, the most common required term for G Fin Tube is seamless Carbon Steel Tube with Al1100 Embedded Fin.
G Embedded type-Fin Tubes
Base Tube material: Seamless SA 334 Gr.6 or SA179 Tube as per ASME Sec II part A.
Base Tube size : 25.4 mm OD x 2.77 mm min thk under fin x Over Fin (15.875 mm height) x 12,192 mm long
Unfinned length: 50 mm on each end.
Fin details : G Embedded type finned, 57.15 mm OD x 393.7 FPM,
Fin material: SB 209 Aluminum Alloy 1100, Fin thk 0.4 mm, Min fin tip thickness 0.2 mm
Usually the fin pull test is required for G Fin as indicated below
1.Select a fin approx 40’’ from the one end of the fin tube carefully push the fin tips away from the fin you have chosen to pull
2.With the point of the fin snips out the chosen fin clear to the outside of the tube. Make 2 cuts 1/2’’ apart and parallel, so that we have a 1/2’’ wide piece of fin to pull on.
3.Attach the fin pulling tool securely by tightening the wing nut, then hook a spring scale to the pulling tool and exert a steady pull.
4.The fin must resist a minimum pull of 4kg (this value may be lower when base tube material is stainless steel or nickle alloy)
Processing technology of G Type Finned Tube
The inlaid spiral finned tube is to pre-machine a spiral groove with a certain width and depth on the base pipe, and then inlay the aluminum strip or copper strip on the steel pipe on a lathe. During the winding finning process, due to a certain pre-tightening force, the aluminum belt or copper belt of the G Type finned tube will be tightly strung in the spiral groove, therefore there will be a certain contact area between the G Fin Strip and the steel pipe.
In order to prevent the G Fin strip from rebounding and falling off, the two ends of the aluminum fin strip will be fixed with staples or with a steel plug. In order to facilitate inlaying, there should be a certain side clearance between the steel strip and the spiral groove. If the side gap is too small and an interference is formed, it will be difficult for the G Fin mosaic process to proceed smoothly. In addition, the wound aluminum strip always has a certain spring back, and as a result, the G Fin strip and the bottom surface of the spiral groove cannot be well joined. G Type Finned Tube can be carried out on general-purpose equipment, and the cost is not high, but the process is complicated and thus the G finning production efficiency is low, especially when the base tube is stainless alloy such as alloy 825 and ASTM B163 N04400 Tube
Application/use of G Type Finned Tube: air cooler, heat exchanger, air heater, economizer
Application fields
●Petroleum, chemical and petrochemical industries
●Natural gas processing
●Steel industry: blast furnace and converter systems
Power generation: Condensation of exhaust gas from steam turbines, condensed water in contact with circulating cooling condensation, fossil and nuclear power plants
●Air Conditioning (Freon, Ammonia, Propane)
●Waste incineration equipment
●Compressor cooler, etc.
To avoid any mistanderstanding on your enquiry, we request you to provide the following datas.
Core Tube (Base Tube) Material and Quantity
Base Tube OD * tube wall thick * length
Fin Type and Fin Material
Fin Dimensions: Fin OD * Fin Thick * Fin Pitch * Unfinned Length at two sides
