ISA TP-973003 [ Withdrawn ] Determining the Required Safety Integrity Level for your Process

standard by The International Society of Automation, 01/01/1997

Full Description

A Safety Integrity Level (SIL) Analysis is the initial step in the Safety System Design Process.Where the HAZOP process normally discovers potential hazards and provides generalrecommendations, the SIL is a specific analysis which defines the Safety Criteria and Mitigation ofhazards which can lead to a significant economic, safety and environmental consequences.

There are three SILs utilized by S84 for Risk Classification, as defined in terms of Probability ofFailure on Demand (PFD). This paper provides a methodology to evaluate and classify risk interms of Consequences, and to determine the SIL for the process under consideration based onthese Consequences and the Process Demand Rate. The methodology can be customized tocomply with existing company standards, and should satisfy many of the critical OSHA 29 CFR -1910.119 requirements.

In addition, the paper addresses the configuration of the Safety Instrumented System (SIS) andthe impact of field devices on the system SIL, including the necessity of redundancy and testing offield devices to achieve and maintain SILs of 2 or higher.

Product Details

Published: 01/01/1997 Number of Pages: 10