Hazard identification

1. Hazard identification

2. Introduction • A Hazard and Operability (HAZOP) study is a structured and systematic examination of a planned or existing process or operation in order to identify and evaluate problems that may represent risks to personnel or equipment, or prevent efficient operation. • The HAZOP technique was initially developed to analyse chemical process systems, but has later been extended to other types of systems and also to complex operations and to software systems. With respect to maintenance, the HAZOP method could be applied with the following objective:

3. HAZOP objective • Analysis of the technical system in order to find weak points where a maintenance task could reduce the probability of failure, and/or the consequence of a failure • Analysis of the maintenance action (procedure HAZOP) where the objective is to identify critical tasks when executing the maintenance.

4. HAZOP procedure • Divide the system into sections (i.e., reactor, storage) • Choose a study node • Describe the design intent • Select a process parameter • Apply a guide-word • Determine cause(s) • Evaluate consequences/problems • Recommend action: What? When? Who? • Record information • Repeat procedure (from step 2)

5. HAZOP process parameters Flow Composition pH Pressure Addition Sequence Temperature Separation Signal Mixing Time Start/stop Stirring Phase Operate Transfer Speed Maintain Level Particle size Services Viscosity Measure Communication Reaction Control

6. Study node • A study node could be a line, a vessel, a pump, or an operating instruction

7. Guide words

9. Example of HAZOP worksheet for the process parameter flow