Eight checks a design verification layer should run

Engineering review is where experience matters most. It is also where a lot of time goes on errors that are not really engineering at all: a missing tag, a balance that does not close, a loop with no final element.

A verification layer exists to catch those first, so that reviewers spend their time on judgement. Here are the checks we think every design should pass before it moves to the next stage.

1. Mass balance closure

Every unit, and the process overall, should close its mass balance within a stated tolerance. A balance that does not close points to a missing stream, a wrong composition or a units error upstream.

2. Energy balance and duties

Exchanger duties on the PFD and datasheets should match the converged simulation. Mismatches usually mean one of them was updated and the other was not.

3. Tag consistency between PFD and P&ID

Every piece of equipment and every stream on the PFD should appear on the P&ID with the same tag, and nothing on the P&ID should be orphaned. This is the most common source of confusion during datasheet and procurement work.

4. Control loop completeness

Each control loop needs a measurement, a controller and a final control element. A level indicator with no valve, or a controller with no measurement, is easy to miss on a busy drawing and easy to check automatically.

5. Line sizing against flow

Line sizes should keep velocity and pressure drop inside the criteria the project has set. The check does not choose the criteria; it applies the ones your engineering standards define to every line.

6. Relief cases identified

Every item of equipment that can be overpressured should have a relief path, and the relevant relief case should be recorded. The check confirms the case exists; sizing the device remains a specialist task.

7. Design conditions consistent with operation

Design pressure and temperature should sit above operating conditions by the margin your project specification requires, and use a consistent basis across datasheets.

8. Revision traceability

Each drawing should reference the current revision of the data it was built from. A P&ID built on a superseded simulation case should be flagged, not discovered later.

What the checks do not do

They do not sign drawings. Criteria come from your project standards, and every flag goes to an engineer who decides whether it is a real issue. The goal is simple: make sure the people reviewing a design are looking at engineering questions, not transcription errors.

Ardsol runs this kind of verification between every stage of its pipeline. See the verification layer.