Track 2 Session 1

9:10 to 10:10 a.m. Wednesday March 28, 2012

HAZOP Applied as an Analytical Method to Determine the Risk of Control System Failures

The Hazard and Operability (HAZOP) study is a well-known method for identifying potential problems in petrochemical and chemical installations. The HAZOP study described in the EN 61882 standard helps to trace all potential problems that can result from the process parameters. New standards issued in conformity with the newest state-of-art deal with all the problems that can occur not only in connection with process parameters but also with control systems.

Because control systems are based on programmable devices, it is not easy to determine all types of problems they may generate due to the fact that it is not possible to define all kinds of microprocessor failures. For the purpose of identifying the majority of hazards appearing in control systems, a Control Hazard and Operability (C-HAZOP) study has been worked out. The C-HAZOP method is based on HAZOP but it is dedicated to analyze only control systems. Special guide words and spreadsheets have been designed for this method. C-HAZOP is the only qualitative method that also provides all necessary information for further quantitative analyses such as FMECA.

Key Words: Hazard and Operability Study

MichaƂ Karolak

UDT [Office of Technical Inspection]