Layout Safety Review

The Layout Safety Review will broadly follow the guidance of API 521.

General principles:

Plant layout is often a compromise between a number of factors such as:

  • The need to keep distances for transfer of materials between plant/storage units to a minimum to reduce costs and risks;
  • The geographical limitations of the site;
  • Interaction with existing or planned facilities on site such as existing roadways, drainage and utilities routings;
  • Interaction with other plants on site;
  • The need for plant operability and maintainability;
  • The need to locate hazardous materials facilities as far as possible from site boundaries and people living in the local neighbourhood;
  • The need to prevent confinement where release of flammable substances may occur;
  • The need to provide access for emergency services;
  • The need to provide emergency escape routes for on-site personnel;
  • The need to provide acceptable working conditions for operators.

The most important factors of plant layout as far as safety aspects are concerned are those to:

  • Prevent, limit and/or mitigate escalation of adjacent events (domino);
  • Ensure safety within on-site occupied buildings;
  • Control access of unauthorised personnel;
  • Facilitate access for emergency services.

In determining plant layout the following is taken into account:

  • Inherent safety
  • Domino effects
  • Fire
  • Explosion
  • Toxic gas releases
  • Positioning of occupied buildings
  • Aggregation / trapping of flammable vapours
  • Segregation of incompatible substances (particularly in warehouses / storage areas)