Iron Ore Pelletizing technical illustration · conceptual illustration
Start with ownership
An interface register should name a responsible party on each side of a handover. “By others” is not an adequate final description. Record the required input, the drawing or specification that governs it, the date needed and the process for approving a change.
Separate the boundaries
Distinguish physical interfaces from functional and contractual ones. A conveyor discharge, a control-system signal and a performance guarantee may concern the same area while requiring different decisions. A single equipment boundary on a flowsheet rarely captures all three.
Plan for brownfield conditions
For an existing plant, state which dimensions and conditions are verified and which still depend on a survey. Track access restrictions, outage windows and temporary arrangements. Give uncertain inputs a visible status so they do not quietly become fixed assumptions in detailed design.
Write the commissioning handover
Define what must be complete before each activity begins and who accepts the handover. Keep documentation, training, spares and operating procedures in the same readiness review as mechanical completion. Where the production team will inherit the equipment, involve it in the acceptance process.
A useful meeting output
Close an interface meeting with a short decision log: decision, evidence, owner, due date and affected documents. Circulate unresolved items with their consequences. The objective is not a longer register; it is fewer ambiguous commitments at the point when the project needs certainty.
Define a screening-to-furnace interface completely
A screen supplier may own the roll bank while the EPC owns the chute, support structure and discharge conveyor. If each party optimises its own item, the assembled system can still deliver uneven feed or create new fines. Define the interface by material behaviour and geometry as well as by a flange or equipment tag.
| Interface | Owner/EPC input | Specialist equipment input |
|---|---|---|
| Feed to roller screen | Flow distribution, chute geometry, peak feed and available headroom | Required feed presentation and acceptable loading envelope. |
| Screen to distribution system | Outlet destinations, transfer elevations and conveyor layout | Discharge geometry, expected stream definitions and maintenance access. |
| Structural support | Support stiffness, alignment survey and erection tolerances | Loads, connection details and permissible equipment alignment. |
| Electrical/control | Power characteristics, interlocks and plant signals | Motor/drive list, permissives, trips and local operating modes. |
| Replacement work | Crane coverage, access platforms and isolation strategy | Component masses, withdrawal directions and service clearances. |
Close an interface with evidence, not a status colour
For each open item, state what document or observation will close it. “Discussed” and “agreed in principle” are intermediate states. A mechanical interface may require a signed drawing; a control interface may require an approved cause-and-effect schedule; a performance interface may require an agreed sampling and test plan.
Keep the basis and revision together. A layout changed after equipment fabrication can invalidate an earlier clearance review. The register should identify dependent drawings and trigger a review when its governing assumption changes. This is particularly important for modifications within an existing plant, where survey uncertainty can be larger than the new equipment’s fabrication tolerance.
Worked example: a capacity mismatch without a faulty machine
Illustrative design case
A screen is specified for 125 t/h total circulating material. The downstream reject conveyor is selected for 20 t/h because a nominal 20% recycle figure was applied to 100 t/h fresh feed. In the steady-state example used in the process guide, a 20% reject fraction of screen feed gives 25 t/h recycle. Both suppliers could meet their individual specifications while the reject conveyor remains undersized.
The correction is to define the denominator and use a common mass-balance case, including the expected transient and peak duties. Add the selected case and its revision to every relevant equipment datasheet. Do not treat “plant capacity” as a sufficient description of every conveyor and feeder duty.
Make commissioning a sequence of verified handovers
Mechanical completion, electrical readiness, controls testing, dry commissioning, material trials and performance acceptance should have distinct entry and exit evidence. A trial delayed by missing upstream material is not the same as an equipment failure. Record cause, duration and responsible interface so later review does not rely on recollection.
The register should also establish who may authorise adjustments, which settings are retained as the baseline and how as-built documentation will be updated. Successful commissioning produces both an operating plant and a reliable record for the maintenance team.
Technical references
References support the underlying principles. Diagnostic sequences, worked examples and procurement questions are original engineering analysis; they are not plant operating instructions or verified supplier performance results.