ISOLATE
A DECISION-TRAINING ENVIRONMENT · HSG253 THE SAFE ISOLATION OF PLANT AND EQUIPMENT
This is not a course you read. It is a plant you operate. You will plan, install, prove, work under and reinstate isolations on live process equipment — and see what your decisions do to the plant.
Everything here is grounded in HSG253 (HSE, The safe isolation of plant and equipment). Section references are given as topic headings from that guidance. This training demonstrator does not replace company procedures, site risk assessment or PTW systems.
Select your track
Suggested path: LIFECYCLE → ENERGY → METHODS → SCENARIO → ASSESSMENT → REPORT. The COACH (top right) is available throughout.
MODULE 01
The HSG253 isolation lifecycle
Isolation is not an event — it is a managed cycle from hazard identification to reinstatement and audit. Each stage has one question you must be able to answer. Select a stage.
Select a stage to see its key question, common failure mode and HSG253 reference.
WHY A LIFECYCLE?
Most isolation incidents are not caused by not knowing what a spade is. They are caused by treating one stage as if it were the whole job — trusting a drawing, skipping a walkdown, proving once and never re-checking, or letting work scope drift past the boundary.
HSG253 structures isolation around: hazard identification and risk assessment; selection of method; installation and identification; preparation of plant; proving and monitoring; permit interfaces; control of changes; reinstatement; and monitoring, audit and review of the isolation system itself.
MODULE 02
Hazardous energy · find every source
Isolation begins with identifying all sources of hazardous substances and energy that could reach the equipment. HSG253 treats an isolation as secure only when every identified source is disconnected or positively secured, and that condition is demonstrated and maintained.
Select a numbered source on the skid drawing.
MODULE 03
Isolation methods · the integrity spectrum
HSG253 ranks isolation methods by the security they provide. Select a method to see how it works, where leakage can pass, and when HSG253 considers it appropriate. The isolation must be matched to the risk — not to habit, and not to the schedule.
MODULE 04 · STATE-DRIVEN SIMULATION
K-101 · intrusive maintenance on live plant
Work order: replace the dry gas seal and bearing assembly on centrifugal gas compressor K-101. The train is live — 40 barg at the suction KO drum, 70 barg to export. Your decisions change the plant state below. Wrong decisions have consequences: the plant will show you what you released.
SHIFT LOG
MODULE 05 · ADAPTIVE ASSESSMENT
Competence assessment
Judgement, sequencing, method selection, hazard recognition and diagram interpretation. Difficulty adapts to your performance. First-attempt answers carry full weight — this is not a guessing game. Scenario findings are combined with your answers in the final report.
MODULE 06