Hazop Pre Concessions

Pillai Sreejith

HAZOP Pre-Concessions The typical HAZOP (Hazard & Operability) pre-concessions are listed here for the benefit of engineers who participate in HAZOP sessions. Unless these pre-concessions are clear to all, the HAZOP will not happen smoothly leading to unnecessary discussions and arguments. Before start of HAZOP session, it is advisable to explain these 10 key pre-concessions in the opening / briefing presentation for the sake of clarity and smooth conduct of the HAZOP workshop. Defining these pre-concessions will also help to maintain the focus of this critical team exercise.

1. HAZOP is not design review. Design reviews should be discussed in a separate session

2. Only instrument / equipment single failures are to be considered. No ‘double jeopardy’ or simultaneous equipment / instrument failure will be considered

3. Operator errors / negligence will not be considered 4. It is assumed that all mechanical protection devices (Pressure Safety Valves, rupture discs, etc.) will always function when required

5. All plant / equipment are well designed, operated, maintained and periodically inspected in accordance with applicable standards and guidelines 6. If there are more than one equipment trains (compressor, for example), only one equipment train / system will be subjected to HAZOP 7. Generally impact on environment will not be considered 8. Equipment selection are deemed suitable for the specified design conditions 9. Failure of instrument gauges will not be considered.

10. Consequences due to natural calamity, objects falling from sky, etc. will not be considered. Compiled by: Pillai Sreejith [email protected]

HAZOP Pre-Concessions/December 2008