Plant 3D structural steel is the part people leave out. It is not the process, so when a model is built to look at the pipework, the steel gets skipped, or thrown in roughly to fill the gap. The pumps and pipes are the point; the structure holding them up feels like background. Leave it […]
Plant 3D structural steel is the part people leave out. It is not the process, so when a model is built to look at the pipework, the steel gets skipped, or thrown in roughly to fill the gap. The pumps and pipes are the point; the structure holding them up feels like background.
Leave it out, though, and the model floats in space.
Plant 3D structural steel is the skeleton everything else sits on: the racks your pipe runs along, the structures your supports sit on, the platforms, stairs and ladders people climb to reach the plant. It is also the thing every change has to fit around. So the steel is not background detail, it is the context that lets the model answer the two questions that matter most: will the new work fit, and can people reach it.
Without it, you cannot check whether a new line clears the rack, whether a new pump lands where the steel allows, or whether an operator can actually get to the valve you have added. The model looks complete and answers none of it.
Skip the steel, or model it from drawings that no longer match, and the problems land late. A new spool that fouls a beam nobody modelled. A modification that does not fit the rack as it was actually built. Access steel left out, so a platform clash or a missing ladder only shows up once people are on site. And steel, more than most things, gets altered over a plant’s life, extended, modified, corroded, so the original drawings are rarely the structure standing there now.
If you own the site, that is rework, and access and safety issues found at the worst possible time. If you engineer the site, it is you routing a pipe through a beam that is really there, then doing it again once the clash is obvious.
Like equipment, the steel tools in Autodesk Plant 3D are built for representation rather than detailing. You model the structure from its parts, steel members, footings, plate, stairs, railings and ladders, and set your shape standards, material standards, codes and sizes so each member is the real section.
For new structures you start with a grid. You lay the grid first, set the spacings for your racking, your support steel or your access platforms, then snap the steel to it, which keeps everything aligned and quick to build.
For an existing site you do the opposite. Rather than an idealised grid, you capture the steel as it actually stands from the laser scan, because it has usually been modified since it was drawn, and every new pipe and piece of equipment has to fit what is really there. This is where Plant 3D structural steel earns its place: the model matches the structure, not the drawing.
A couple of habits make it manageable. Build your Plant 3D structural steel in its own model and xref it into the pipework models, which keeps each model smaller and easier to handle. And use the display toggle: a full 3D shape is heavy for your machine to compute, so you can switch the steelwork to a simple line representation while you work, and save the full shape for when you need it.
Where Plant 3D structural steel runs out of road is detailing: the connections, gusset plates, bolt sets and welds that fabrication needs. For that you export the model to Autodesk Advance Steel, a full steel design and fabrication package, and build the detail there. If you already hold an Advance Steel model, it works the other way too, and you can xref it straight into Plant 3D. The properties you set against the steel also feed your reports, so the model can give you tonnage and material quantities for estimating and procurement.
This is our work. For an existing site we build your Plant 3D structural steel exactly as it stands from the laser scan, so new pipe and equipment fit the structure that is really there, not the one on a drawing from years ago. We model the access steel too, the platforms, stairs and ladders, so reach and safe access can be planned before anyone is on site. And where you need fabrication level detail, we hand off cleanly to Advance Steel.
If your model has no Plant 3D structural steel in it, or steel that no longer matches the site, it cannot tell you whether your next job will fit. That is usually the first thing you need to know.
Next in this series: The Breakdown of Plant 3D Pipe Supports.
