Representative concept / reconstructed for portfolio clarity Not an original shipped screen. All values are illustrative. Back to case study D3

Diagnostic investigation: high pressure, Boiler-01

Incident INC-2025-0512 · Alert raised 09:15 · Asset Boiler-01 (generic tag) · Investigation opened from the alarm list

CriticalAwaiting engineer reviewIllustrative data

Event summary

Event
Boiler pressure high
Observed value
9.8 bar
Threshold
> 8.5 bar
First detected
09:15
Asset
Boiler-01
Related past incidents
INC-2025-0481, 0467, 0452

Correlated signals Pressure and control-valve position on one time axis

Boiler-01 pressure and control-valve position, 08:45 to 10:15 (illustrative) Pressure rises from about 7.6 bar, crosses the 8.5 bar threshold at 09:15, reaching about 9.8 bar. The control-valve position starts falling about 15 minutes earlier, from about 62% to about 35% open, and stays there. 7891020%40%60%08:4509:0009:1509:3009:4510:0010:15 Threshold 8.5 bar 09:15 alert
Pressure (bar, left axis)Control-valve position (% open, right axis)Alarm threshold

Evidence What has been observed or recorded, kept separate from interpretation

  • E1 · Pressure above threshold since 09:15Observed signalPressure transmitter, Boiler-01. Peak 9.8 bar against an 8.5 bar limit.
  • E2 · Control valve partly closedObserved signalValve position feedback fell from about 62% to about 35% open before the pressure rise.
  • E3 · Pressure moves with valve positionDerived correlationCorrelation over the same window. Correlation does not establish cause.
  • E4 · Valve maintenance overdueMaintenance recordScheduled service for the pressure control valve is past due.

Candidate hypotheses Proposed, not confirmed

H1 · Faulty pressure control valveSupported by E2, E3, E4. Suggested by the analysis assistant; requires engineer confirmation.
H2 · Pressure sensor calibration overdueFrom the cause map (D2). No supporting evidence linked yet.
H3 · Inadequate pressure-relief procedureFrom the cause map (D2). Not yet assessed.

No likelihood or confidence score is shown: none has been validated for this workflow.

Human review

  1. Event detectedAlarm raised automatically, 09:15
  2. Signals correlatedPressure and valve position aligned in time
  3. Evidence and hypotheses reviewedReviewer: on-shift process engineer
  4. Decision: confirm or reject H1Pending
  5. Action and hand-off recordedPending

Decision not yet recorded.

Proposed next steps Require approval

  • Replace pressure control valveOnly if H1 is confirmed
  • Verify system pressure after replacement
  • Update the preventive-maintenance schedule