Typical situation
A plant runs a dilute-phase pressure conveying system. Pressure blower 1 picks up under four outdoor silos, each with a butterfly valve and a rotary airlock with a blow-through adapter, and level indicators on every silo. The conveying line runs into the building and up to the second floor, where a gain-in-weight scale hopper on load cells receives the material and discharges to a mixer. The mixer discharges to a surge hopper with its own rotary airlock and blow-through adapter, and pressure blower 2 conveys from there to a bulk bag filler. The bulk bag sits on a floor scale, so the fill weight can be checked.
Before changes are designed, including a fifth silo planned for the pickup line, the plant needs the system as it’s installed today. Drawings of conveying systems rarely show how the lines were actually routed.
The scope is set up by a designer who lays out pneumatic conveying systems, so the model focuses on what line design needs: routing and bends, elevations where the line crosses the building, the pickup and receiver connections, and clearances along the route.
What this scope includes
- Tier 1, scan. About 6,000 sq. ft. at the standard-industrial rate: the outdoor silo and blower pad, plus each indoor floor the system passes through that needs capture. Setups follow the conveying lines from the silo pickups to the scale hopper and on to the bag filler, so bends and connections are captured from more than one side. Silo tops and their level indicators are captured where they can be seen safely.
- Tier 2, building. Floors, walls, ceilings, roof geometry where safely captured, stairs, doors, and building-access ladders on each captured floor, plus the outdoor pad, so the route has its column lines, wall penetrations, and overhead clearances.
- Tier 3, process. Limited to the agreed 2,500 sq. ft. process area: external geometry and major visible connections of the silos and their butterfly valves, rotary airlocks, blow-through adapters, and level indicators; both blower packages; the scale hopper and its load cells; the mixer; the surge hopper and its airlock; and the bulk bag filler with its floor scale. The conveying lines are modeled down to the agreed minimum size, with platforms, ladders, and guardrails.
- Planned tie-in. The point on the pickup line where the future silo will connect is flagged in the model. It’s a fabrication-critical point, so it’s verified separately before anything is fabricated, as the note below this description explains.
Why the minimums matter here
At this size, the per-square-foot math falls below the published minimums on most lines, so the minimums set most of the budget. The breakdown on this page shows which ones apply.
Minimums apply per project. If nearby areas also need documenting, adding them to the same scope spreads the minimums over more square footage.
What’s excluded
- Conveying calculations, P&IDs, and fabrication drawings, which are separate scopes
- Design of the future silo and its connection
- Equipment internals, including the inside of the silos, hoppers, mixer, and airlocks, and detailed supports
- Calibration or checks of the scales and load cells
- Drawings (Tier 4 scope)
Fabrication-critical tie-ins, flange locations, anchor bolts, and tight-clearance dimensions need separate verification before fabrication or installation, quoted separately. Verification rule