Definition:
The main interlock list (MIL), which can be called various other things, define how Safety Instrumented Functions (SIFs) and other critical protective functions relate to process events and system responses.
This document can and will be called many different things. It is often done on a spreadsheet tool.
Is often call a cause and effect diagram or an interlock list.
Key Points:
- The Main Interlock List is often the master document coordinating shutdown system design.
- Interlock Lists catalog all automatic trips and shutdown actions.
- Not technically required in a SIS design as other documents such as functional narratives or logic diagrams may be sufficient.
Example:
A high pressure trip causes an automatic closure of the inlet valve and shutdown of the feed pump as shown in the Cause and Effect diagram.
See also: Functional Narrative, Logic Diagram
Cited Source:
- ISA TR84.00.03-2002.