ISA TR84.00.03

Scope and purpose

A process hazards analysis is used to identify the safetyfunctions necessary to reduce the risk of identified hazardousevents. When a safety function is implemented in a safetyinstrumented system (SIS), the risk reduction required from thesafety instrumented function (SIF) is related to one of fourdiscrete safety integrity levels (SIL). The function and system aredesigned and managed according to ANSI/ISA-84.00.01, whichestablishes requirements necessary to claim the specified SIL forthe SIS throughout its life.

A critical aspect of maintaining the SIL is the implementationof a mechanical integrity (MI) program that monitors the installedperformance of the SIS equipment and takes corrective action whenthe performance does not meet the requirements. This technicalreport is an informative document providing guidance onestablishing an effective MI program that demonstrates throughtraceable and auditable documentation that the SIS and itsequipment is maintained in the “as good as new” condition

This edition of ISA-TR84.00.03 provides considerations forestablishing an MI program for SIS; it focuses on how to plan andimplement a comprehensive MI program rather than including specifictest procedures as in the previous edition. This technical reportdoes not provide complete details on how to safely or fully executeall MI activities in an operating facility. Individuals who areassigned responsibility for MI activities must determine what isnecessary to maintain the safety integrity of a specific SIS.

The MI program involves many activities that occur throughoutthe SIS lifecycle, but it predominantly focuses on the timelydetection and correction of incipient/degraded conditions andcomplete failures to ensure that the SIS operates as specified whenrequired. Rigorous inspection and complete proof testing isrequired for all SIS equipment whether existing or new. While thefrequency of these activities may vary due to the required SIL, thepurpose and goal of inspection and proof testing are not affectedby the SIL.

Inspection and proof testing is required to:

• meet regulatory requirements

• meet ANSI/ISA-84.00.01 requirements

• meet equipment manufacturer requirements (e.g., safetymanual)

• demonstrate through witnessed test and preventive maintenancerecords that the equipment is being maintained in the “as good asnew” condition

• detect and correct unrevealed failures

• verify that the MI program and test interval are sufficient toensure functional and integrity requirements are met for theequipment life

• monitor equipment for degradation mechanisms (incipient anddegraded) which may compromise future performance

• identify when equipment has reached wear-out and requiresreplacement

• provide data and information to facilitate the evaluation ofMI program success and to support continuous improvement

The technical report addresses:

• the identification of personnel roles and responsibilitieswhen developing an MI plan,

• important considerations in establishing an effective MIprogram, and

• detailed guidance and examples to support user -specific workprocesses as part of an overall MI program.

Edition:

12

Published:

08/28/2012

Number of Pages:

152

File Size:

1 file , 1.6 MB