Engineering design and fabrication of steel structures should be carried out in accordance with national standards, rulesand regulations. Strict quality control on each stage of fabrication of steel structures, starting from acceptance of raw material, flattering, shot-blasting, fabrication of sing elements, assembly, welding of elements, carrying out of general and check assembly before application of anti-corrosion coating, primer, paint application and ending with loading of structures to the transporting vehicles.
On the major stages of fabrication of steel structures needed to ensure assemblability of buildings and structures on site - is a check assembly.
General assembly of steel structures
General assembly of structures is assigned in accordance with KM projects. It is needed in order to ensure designed manufacturing accuracy. The following activities are performed:
In general big-dimensioned and structures with big spans are subjected to general assembly, among them: crane runways, rafter and secondary trusses, columns, girders, frames, arches, support and conical parts of chimneys and silos, oversized plate structures (bins, air ducts, shells for blast furnaces, etc.).
Check assembly is used if a big batch of elements of the same type is manufactured. Neither fitting, nor special marking operations are not performed during check assembly, as all fabricated shipping elements should be interchangeable. Check assembly is used to test manufacturing accuracy of single shipping elements, fixing equipment and accuracy of geometrical dimensions of the whole structural element, consisting of two and more shipping elements (frames, trusses, columns). The common practice is to check assemble every first structure fabricated with the help of new or repaired fixing equipment, further on - every tenth manufactured piece is checked.
General and check assemblies are the obligatory production stages and are the part of processing procedure which completely eliminates manufacturing errors. This in its turn, increases the quality of erection works at site hence saving money and time.