SPIRO GILLS Products Brochure - L.B.L Trading Ltd.

EXTRUDED FINSSG-K Fin(Knurled L Fin)Application: Standard finfor medium-temperatureapplications, giving increasedatmospheric corrosionprotection to the outersurface of the base tubeUpper limiting temperature:250°CManufacture: Fin foot ispre-formed into an L shapeand applied to base tube undertension. Knurling tools bothprecede and follow the layingdown of the fin foot so that thefin material is locked into thepre-knurled tube. This gives upto 50% greater thermal contactarea than standard L fin andalso ensures an airtight fin totube bond, resulting in greatertube protectionFin materials: AluminiumBase tube materials:Any metallic materialStandard dimensionsof applied fin tubes:Base tube dia. (mm):25.4, 31.8, 38.1, 50.5, 50.8Fin height (mm):9.5, 12.7, 15.88Fin pitch:236 to 433 fins/metreSG-Extruded Fin(Bi-metallic Fin)Application: High-efficiencyfins for higher temperatureapplications giving completeand permanent atmosphericcorrosion protection of the basetube. Using over 40% morealuminium than the equivalentapplied fin, the extended fin isvery robust and resistant tomechanical damage, allowingthe finned tubes to be cleanedwithout damage using eithersteam or high-pressure waterUpper limiting temperature:300°CManufacture: A carefullydegreased core tube is fitted intoan aluminium primary tube.This assembly is then fed intothe triple-spindle finning headof the fin-extruding machine.Three special multi-disc packsextrude the aluminium tube intohelical high fins while reducingthe inner diameter to give firmpressure contact with the core tubeFin materials: AluminiumBase tube materials:Any metallic materialStandard dimensionsof extruded fin tubes:Base tube dia. (mm):25.0, 25.4, 31.8, 38.1Fin height (mm):15.88Fin pitch:354, 393, 433 fins/metre13