Longitudinally finned tubes are manufactured by resistance welding method with overlap (Lap seam welding, method 221 / RSEW). 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. Fins can be in plain, “cut and twist” or perforated execution. 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 tube from 16 to 168 mm Wall thickness of tube from 5 to 8 mm Fin height from 5 to 32 mm Fin thickness from 0,8 to 2 mm Tube length from 800 to 11000 mm This type of finned tubes is used in power generation, petrochemical and chemical industry for heaters, heat exchangers, coolers and other.
Mar 20, 2012 - At the conclusion of the first part, dealing with the gerund, is a. I trojka, rvanuvsls* 1 stu5a po doskam, vyletela Iz kai^tnika, sverkaja lakom 1 med'ju koljaaki, kldaja svezirai kom'jaml o kopyt pristjaznykh,. Rasdaetsja rezklj Sipjasc'ij zvuk. Zalivajas* podobrannymi bubencami, -opisala. Jan 09, 2017 Dunav - Beovuk 74:72, Trojka Matijasevica uz zvuk sirene KK Dunav. Unsubscribe from KK Dunav? Cancel Unsubscribe. Subscribe Subscribed Unsubscribe 92.