Metal Structure Design: KM and KMD Drawings, Loads, Codes
Before metal gets cut, a load-bearing structure has to be calculated and detailed — here is what design involves and what is required from the customer.
Why design is a separate stage
For light, non-critical structures a sketch is sometimes enough, but for load-bearing frames, pipe racks, equipment supports, and any structure carrying real load, design is mandatory — it determines profile sections, plate thickness, and the number and type of welded and bolted connections. A mistake here is invisible until installation or the first real load, so it is not worth cutting corners on engineering.
The KM stage — structural design
The KM stage develops the structural calculation model and selects member sections against the full set of loads: permanent (self-weight and equipment weight), variable (snow, wind), process (equipment vibration, thermal loads), and, in some regions, seismic. The output of the KM stage is general arrangement drawings, member and joint layout schemes, and a steel specification.
The KMD stage — fabrication detailing
KMD (fabrication detail drawings) translates the KM design into drawings the plant uses to cut and assemble the metal: detailing of every part, joint drawings with welds and bolted connections called out, a rolled-steel specification by grade and section, and a shipping-mark schedule for site assembly. Without KMD, the shop works from an interpretation of the KM drawings, which raises the risk of cutting and assembly errors.
Regulatory basis
Calculation and design follow the applicable building codes (SP, SN RK in Kazakhstan), which govern load collection, allowable stresses and deflections, weld requirements, and corrosion protection. For sites in Kazakhstan, regional snow and wind load maps and site seismicity are also factored in.
What the customer needs to provide to start a project
A minimal package to start work: a technical brief or sketch with dimensions and the structure's purpose, load data for equipment to be mounted on it, corrosion-protection requirements, and, for a tie-in to an existing facility, survey data or drawings of adjacent structures. The more complete the input data, the fewer revisions during KMD and the more accurate the final quote.
Design timeline
For a standard frame or a simple support structure, the KM and KMD stages take from a few days to a couple of weeks; for large or non-standard projects, longer, due to approvals and coordination with related disciplines (foundations, utilities). Overlapping design with fabrication of already-finalized assemblies shortens the overall lead time.
Need a metal structure design for your project?
UK-ZTO-AN handles the full cycle — from calculation and KM/KMD drawings to fabrication and installation. Send us a brief or a sketch and we will estimate the design timeline.