Production processes

Materials Delivery – Quality Test and Sheet Depot

With the delivery of the required materials and the compliance of their specifications with the standards determined by the laboratory, the manufacturing and production operations will be started at Dena Industrial Group.Dena factories are equipped with the advanced tracking and coding system using the labeling operations. for every component, according to the processes, some labels are prepared which by the completion of each step for each component, its code is recorded in the system by the barcode reader device. this system can provide information relating to each project for users, including the number of components in the production line, the amount of constructed – colored – components ready to carry and the details of components carried to the project site.

Preparing Shop Drawings

Technical engineers translate structural designers drawings to the construction and implementation language. by considering the amount of materials application and the structures construction and installation conditions, for each product, an optimal workshop executive drawing is prepared. After preparing shop drawings, welding procedure specification (WPS), procedure qualification record (PQR) based on iranian welding regulations (publication 228) and international standard AWS S.1.1 and obtaining the letter of confirmation from the employer and adviser, the construction and production operations will be started.


First, sheets cutting plan is prepared by experienced engineers using the latest software in the world and sheets are forwarded to the cutting section. sheets cutting is done by two hot and cold methods. one of the devices used for the hot cutting is CNC which has the ability of straight cutting and modeled cutting for all sheets with different thicknesses. the high technology of CNC cutting devices used in Dena factories leads to the maximum accuracy in cutting components and makes it possible to cut components with special shapes designed and drawn in the software environment. hot cutting devices are supplied by an oxygen tank and town gas which is done by tubes along production saloons and they will be attached to the tank. cutting sheets with 6-12 mm thickness is done by 3m & 6m guillotine device. After cutting sheets, in component which need edges based on WPS, the construction of edges will be done by two hot and cold methods using automatic beveling machines and rail cutting machine. Sheets cut by the rolling device are completely smoothened are forwarded to the assembly section.

Metal Strips

For the assembly of columns or beams, first sheets will be belted based on shop drawings by the gas metal arc welding (GMAW) process which its consumed gas is a combination of argon gas and carbon dioxide with very high purity and will be supplied by the respecting tanks. welding the seam between belts which has the role of belts connection must be done based on the confirmed WPS in an intrusive form by skillful welding manpower with welding certificate from technical and vocational organization in order to make the belt act uniformly all over the component and elements. According to the type and degree of significance of welding operations, they are done by experienced experts of welding inspection companies using nondestructive tests (NDT), including visual test (VT), penetrant testing (PT), magnetic particle testing (PT) and ultrasonic testing (UT).

Radial Work

in buildings with nuts and bolts connections on components, based on the type and size of bolts in the confirmed shop drawings, some holes will be made by the radial device. Radial work unit is one of the very accurate and planned units of the organization where each device performs the wing and body drilling of columns and beams. Connection flanges are prepared in separate saloons by advanced machines, including Drill CNC machine which has a significant role in the speed and production of components, and will be strapped and packaged for transferring to the installation site.

Columns and Beams Assembly and Stiffeners Installation

Metal strips are ready for assembly and turning into columns or beams. The four-dimensional assembly of boxes is done using semiautomatic box making and H making machines and or by the most skillful assemblers in specified fixtures. Using semiautomatic machines for the box assembly leads to the increase of quality, reduction of construction errors, observance of allowable regulative tolerances; increase of production speed, and reduction of manpower expenses. in the next step, horizontal stiffeners are installed on the component. These stiffeners inhibit the section deformation and members condensation. After installing stiffeners, three dimensions out of four dimensions of boxes are welded and the fourth dimensions welding is done after the assembly by electro-slag device. For vertical welding of components with high thickness and welding volume, the submerged arc welding method is used (by automatic gate machine) which is one of the modern processes in the welding industry.

Installation of Additional Components

This step includes the installation of additional components for columns, including pickets of the clipped connection, joint connections sheets, gear cutting, etc. The swing of initial additional components of columns and beams will be removed using the straighter machine and they will be ready for transferring to the additional components installation unit. The unit of additional components installation on products is very sensitive because in case of the occurrence of error, its correction is equal to the loss of structural mechanism of the member.