Controls & Protection
Safety Instrumented System (SIS)
An instrumented protection layer that performs defined safety functions independently of normal process control when specified hazardous conditions occur.
Why it matters
Understanding the separation between normal control and protective logic is central to safe operation, testing, bypass governance and change management.
Related technical topics
Controls & Protection · Intermediate
DCS, SIS and Emergency Shutdown Systems
Understand the different roles of the distributed control system, safety instrumented system and emergency shutdown functions in an LNG facility.
Safety Systems · Advanced
Process Hazard Analysis: HAZOP and LOPA Concepts
Understand how structured process-hazard studies identify deviations, causes, consequences, safeguards and risk-reduction needs in LNG facilities.
Valves & Protection · Intermediate
Emergency Shutdown Valves (ESDVs)
Learn how ESDVs isolate inventories or process sections during defined shutdown scenarios and how valve fail position, actuator design and shutdown logic fit into the protective architecture.