Functional Safety 2016

InstMC FS2016 (Rev 3.0)

Page

Nicol Instrument Engineering Limited

IEC 61511 ADDITIONS AND REVISIONS

ABSTRACT

The paper will look at the key changes in requirements introduced by the publication of IEC 61511-1

Edition 2.0, which should help the users of the standard to consider actions for their Safety

Instrumented Systems.

It should be noted that whilst the paper will focus on key technical changes there may be important,

to the user, minor technical changes that are not included or highlighted, and thus it is the duty of the

user to understand all the requirements in the standard and how they may impact on their facility.

INTRODUCTION

The long awaited Edition 2 of part 1 was issued February 2016. At time of submitting this paper (August

2016) the revised Parts 2 and 3 were still to be issued.

As with most standards revisions there are generally different type of revisions; such as technical,

typos or editorial.

This edition is a technical revision, with significant technical changes with respect to the previous

edition, and cancels and replaces the 2003 edition.

This paper will only look at the technical differences between the two standards and will not touch

upon any grammatical edits.

The compliance requirements of the standard (clause 4) has not changed (e.g. users to show

compliance with Clause 5 through Clause 19), however technical requirements have changed.

A user who could demonstrate compliance with Edition 1 (2003) may not be fully compliant with the

technical requirements of Edition 2.0. However, the user may consider Clause 5.2.5.4 which allows for

existing SIS designed and constructed in accordance with code, standards, or practices prior to this

standards issue (Edition 2.0) the user shall determine that the equipment is designed, maintained,

inspected, tested, and operating in a safe manner.

The user may read this Clause as a grandfather Clause, but should note that they still have a duty to

determine

that the equipment is designed, maintained, inspected, tested, and operating in a safe

manner.

The structure of the paper is intended to aid the reader with a layout to match each Clause in the

standard.

KEY CHANGES

Clause 3.0 Terms, definitions and abbreviations

The section title has changed to “Terms, definitions and abbreviations”, and the order within the

clause has also changed with the “Abbreviations” now following “Terms and Definitions”.

Terms and Definitions

The changes in the definition cover clarifications, alignment with other references, deletions and

additions.