Explain Shutdown Logic with Diagram?

Shutdown logic diagram (also known as ESD logic diagram) shows a hierarchy of shutdown level within a plant or platform.

Shutdown logic diagram start from telling a big picture of shutdown level, typically the level starts from 0 continues with the higher number (1, 2, …). The lower number represents the more critical shutdown. The subsequent sheets continues with detail hierarchy for each process unit.

Shutdown logic diagram describes the ‘cause’ that may trigger the shutdown and the effect that may results once signal is activated. This diagram also shows the action such as time delay, start-up inhibit, reset that will be performed for each action.

The location of each instrument that act as a trigger/cause shall be specified clearly.

Reference document: SAFE Chart, philosophy

SAFE chart presents the required safety devices for each process equipment. SAFE chart shall ensure all safety requirements have been fulfilled and what executive actions the safety devices have to take.

Philosophy provide the narration and engineer shall translate it to cause and effect interaction so that the plant operates as the intended philosophy.

The purpose of Shutdown logic diagram

Shutdown logic diagram may be used as a reference in preparing cause and effect diagram.

Example of Shutdown logic Diagram Drawing

Shutdown logic Diagram Drawing.pdf (41.8 KB)