Soft regime is being used (direct welding with side current). Fins are welded always in pairs on the opposite sides of the tube. Fins are in the shape of U-profile with the contact surface modified according to system PARSFIN®. This solution in comparison to classic shape of contact surface offers better efficiency of heat transfer, improves the strength of the joint and helps to achieve an even distribution of the fins on the circumference of the tube. Fins are shaped by gradual rolling which results in minimum inner stress in the final profile. Another advantage this method brings is the maximum achievable length of the profile of 7 meters. The fins are usually manufactured from carbon steel (which offers good heat transfer), but they can be manufactured according to the request of the customer and according to the use from high-strength steel, Cr-Mo-Ni steels, austenitic, ferritic and duplex steels. Height of the fin can range from 5 to 32 mm, the angel depends on the specification of the customer. Seamless tubes are used in the same material range as the fins, that means from carbon up to duplex steels (ASTM, EN, GOST). The method and way of production ensure that we can manufacture longitudinally finned tubes in tolerances ± 6 mm.
Outer diameter of base tube: from 16 mm to 168 mm Wall thickness ot base tube: from 2 to 8 mm Fin height: from 5 to 32 mm Fin thickness: from 0,8 to 2 mm Length of tube: from 800 to 11 000 mm
Extruded tubes can be made from one piece or from 2 different material (bimetealic). The core tube material is usually corrosion resistant steel, but any type of material can be used such as carbon and alloy steel as well as coipper alloy and titanium.
Thistype is used mostly in petrochemical and chemical industry, power generationfor steam coils, coolers, air pre-heaters, heat exchangers and others.
High finned tubes L, LL, KL, G
Finned tubes with aluminium fin in type L, LL, KL and G
The fin is fixed to the tube by high frequency resistance welding process according to „International Standard for Dimensions, Tolerances and Tests of High Frequency Resistence Welded Fins“.
Fins can be either SOLID or SERRATED.
The base tubes can be made of carbon steel, alloy steel, stainless stell or duplex and the fins mostly from carbon steel (commonly DC01 or DC04) or stainless steel (usually TP410S, TP409, TP304, TP316 or 316Ti and TP310S).
This type is used mostly in petrochemical and chemical industry, power generation for air-conditioning systems, coolers, air pre-heaters, steam condensers and others.
Studded tubes are made of base tube on which studs are welded by resistance welding process.