Conical columns ERW
COMPARISON AND ADVANTAGES
The conical columns ERW from hot rolled steel sheet disclose important advantages compared to the traditional conical columns employed up to now.
DESCRIPTION
Conical columns with circular section made of hot rolled steel sheet obtained by molding of a steel plate trapezium on purpose made mold in order to give a perfect circular shape. The bent conical profile is closed joining the longitudinal hem by die casting; the hems to be joined are heated up to the melting temperature, by means of high frequency electricity passage, then the profile is pressed by means of rollers obtaining the fusion of the hems. The extra metal generated during the pressure welding process is completely hot removed, obtaining a smooth profile. The die casting process ERW (electrical resistance welding), consists in autogenous wedling where the material composes the part to be joined, guaranteeing the total continuity on the material characteristics.
MATERIAL
The steel that can be employed can be steel grade S355, S275 or S235 having characteristics as per standard EN10025 according to the structural needs.
WORKS
Works can be customised according to the drawing, such as, base plate, opening with flush type door obtained by cutting, drilling, threading, welded details, bending, etc.
PROTECTION
Protection against corrosion by means of hot dip galvanization obtained with the following cycle: degreasing, pickling, washing, fluxing, pre heating, hot dip galvanization in melted zinc bath at 440÷450°, with minimum percentage of zinc into the bath 98.5%. Coating obtained according to UNI EN ISO 1461 with minimum thickness 55 microns and average 70 microns. External painting, if any, with colour from our colour card, rough effect, obtained with thermosetting powders cycle including: cleaning from zinc coating burs; smoothing of the surfaces by means of a light mechanic device; cleaning of the surfaces in order to eliminate grease or dirty and create a good adherence base; application by means of electrostatic spray of polyester powder suitable for galvanized surfaces for outside installation, polymerization into oven at constant temperature of approx. 200°, package for each column, by banding with tissue 100% polyester, (no pluriball), in order to avoid damages during the handling phase. Characteristics of the obtained coat: Cycle C4DUPLEX = cathodic protection double coat, average film thickness 130 microns (70 galv+60 top coat) Cycle C5 Plus = cathodic protection + barrier effect average film thickness 190 micron, (70 galv+ 60+60 primer and top coat) Restistance to mechanical test ISO1519, ISO2409, ISO1520, STM D2794, ISO2815 Resistance to chemical test ISO9227, ISO6270, ISO3231, EN2260-1, ISO2810, ISO11341-1; ISO11507
MARKING
The columns will be CE marked according to the standard in force (DPR246/93, 89/106/CEE; 93/68/CEE). If employed in public lighting, the label on each column quotes: standard reference EN40-5, manufacturer’s identification, certificate number of the authorization to the mark CE CPD P029, year of marking, product code, and contract reference number. If employed in other strucutral fields, according to the CE are manufactured according to EN 1090 execution class ECX2, certificate issued by third party according to European directive UE 305/2011. The marking, on each column quotes, standard reference EN 1090, manufacturer’s identification, certificate number of the authorisation to mark CE 0475-CPR 15, year of marking, product code, contract number.
DESIGN
To design lighting column You need to know the following data:
– design wind speed
– features of the surrounding landscape that is ground roughness category
– height up to the lighting source
– number, type, dimensions and weight of the fixture to be installed
– fixture arrangement (post top; or brackets)
DIMENSIONS
Tolerances on dimensions UNI EN 40/2 - UNI EN 10051
Other dimensions can be realised on demand according to the following dimensional restrictions: maximum length in one section 12,8m; 16m in 2 overlapped sections. Taper ratio from 8 up to 15 mm/m; Maximum base diameter 280mm; minumum d. on top 60mm steel thickness from 3 to 4mm.