HAZOP Studies, Functional Safety, SIL Assessment / classification with LOPA

-The Hazop chairman prompts the team for deviations from design intent which could lead to hazardous events

-The Hazop team discusses Credible causes for the deviations and evaluates the potential consequences

-If the consequences are significant , then existing safeguards are evaluated in terms of their adequacy.

-If existing safeguards are not adequate, then additional safeguards are recommended as action items.

The objective of a HAZID study (Hazard Identification) is to identify:

- The impact of the environment and the surroundings on the facility,

- The impact of the facility on the surroundings and the environment,

- The impact of the various equipment and human aspects with-in the facility,

- General hazards

Note that the HAZID study focuses on non-process hazards

LOPA Objectives

To identify the Independent Protection Layers (IPLs)
To determine residual risk by taking into account the different Layers of Protection
To evaluate the need to further mitigate the risk by implementing SIS(Safety Instrumented System) which carries out a given SIF(Safety Instrumented function)
To select the SIL (Safety Integrity Level) of a SIS (Safety Instrumented System)

The SHAH Gas Expansion Project - a critical analysis of the process design