ISA TR84.00.02 PART 2

W/D S/D BY ISA TR84.00.02

ISA-TR84.00.02-2002 – Part 2 is informative and does not contain anymandatory requirements. Thispart of the technical report is intended to be used only after athorough understanding ofISA-TR84.00.02-2002 – Part 1, which defines the overall scope.ISA-TR84.00.02-2002 – Part 2provides:

a) technical guidance in Safety Integrity Level (SIL) Analysis;

b) ways to implement Safety Instrumented Functions (SIF) to achieve aspecified SIL;

c) failure rates and failure modes of SIF components;

d) diagnostics, diagnostic coverage, covert faults, test intervals,redundancy of SIF components;

e) tool(s) for SIL verification of SIF.

ISA-TR84.00.02-2002 – Part 2 provides one possible technique forcalculating PFDavg values forSafety Instrumented Functions (SIF) installed in accordance withANSI/ISA-84.01-1996, “Applicationof Safety Instrumented Systems for the Process Industries”.

ISA-TR84.00.02-2002 – Part 2 provides the engineer(s) performingdesign for a SIF with a relativelysimple technique generally following the simplified equation approachfor assessing the capabilityof the designed SIF.

The procedures outlined in ISA-TR84.00.02-2002 – Part 2 provide theengineer with steps to followin estimating a mathematical value for PFDavg for typicalconfigurations of SIF designed accordingto ANSI/ISA-84.01-1996. This procedure is appropriate for SIL 1 andSIL 2 SIFs. This procedureshould not be used for SIL 3 SIFs unless the User has a thoroughunderstanding of the SILVerification mathematics and fully understands the limitations of thesimplified equations.

ISA-TR84.00.02-2002 – Part 2 does not cover modeling of externalcommunications or operatorinterfaces. The SIL analysis includes the SIF envelope as defined byANSI/ISA-84.01-1996 (seeFigure I.2).

Edition:

02

Published:

06/17/2002

Number of Pages:

44

File Size:

1 file , 230 KB