(86e) A Case Study of Safety Integrity Level (Sil) Assessment and Verification at Air Products and Chemicals : Electronics Division Product Line Evaluation and Analysis

With the adoption of IEC 61511 and ANSI/ISA-84.00.01- 2004, Air Products and Chemicals has made a concerted effort to provide a standardized approach to the design and implementation of Safety Instrumented Systems following the safety lifecycle model. This presentation provides a Case Study describing the methodology used during the Safety Instrumented System (SIL) Assessment and Verification of existing Electronics Division product lines. SIL Assessment was accomplished through the use of Hazard Identification; Likelihood, Consequence and Risk Analysis; and Layer of Protection Analysis. Each of the Electronics Division Product's Safety Instrumented Functions (SIF) were identified during SIL Assessment. A target SIL was determined for each SIF through quantitative and qualitative analysis. SIL Verification was accomplished using Fault Tree Analysis in order to determine the average probability of failure on demand (PFDavg) for each SIF. This analysis was a joint collaboration between the Process Safety and Process Controls Engineering teams.