Consequence Analysis

There are two types of consequence analysis in API RP 581. They are described below.

Effects of Failure

Many people and things may be affected by a failure. Examples include people, property, environment, and the business.

Effects of failure are calculated based on:

• Type of process fluid
• State of process fluid (solid, liquid or gas)
• Key properties of process fluid (MW, NBP, AIT, others)
• Process operating variables (such as T and P)
• Mass of inventory available for release
• Leak size
• State of the fluid after release in ambient conditions

Types of Analysis

Level 1

This analysis contains all information found within standard and all thermodynamic and dispersion equations available for the selected representative fluids. Level 1 analysis is limited to single phase systems of the select representative fluids. A level 1 analysis is performed by ReliaSoft's RBI software. Area and financial consequences are measured.

Area Consequences

• Component Damage Consequence Area for Flammability
  • Estimated area where damage to equipment from flammability due to loss of containment may occur.
• Personnel Injury Consequence Area for Flammability
  • Estimated area where injury to personnel from flammability due to loss of containment may occur.
• Personnel Injury Consequence Area for Toxicity
  • Estimated area where injury to personnel from toxicity due to loss of containment may occur.
• Personnel Injury Consequence Area for Non-Flam Non-Tox
  • Estimated area where injury to personnel not based on flammability or toxicity due to loss of containment may occur.
• Overall Consequence Area for Personnel Injury
  • The largest area of the three possible personnel injury areas.
• FINAL Component Consequence Area
  • The larger area between component damage and overall personnel injury areas.
• Percentage of Toxics in Process Fluid (wt%)
  • The overall amount of toxics found within the process fluid.

Financial Consequences

• Component Damage Consequence Area for Flammability
  • Estimated area where damage to equipment from flammability due to loss of containment may occur.
• Personnel Injury Consequence Area for Flammability
  • Estimated area where injury to personnel from flammability due to loss of containment may occur.
• Personnel Injury Consequence Area for Toxicity
  • Estimated area where injury to personnel from toxicity due to loss of containment may occur.
• Personnel Injury Consequence Area for Non-Flam Non-Tox
  • Estimated area where injury to personnel not based on flammability or toxicity due to loss of containment may occur.
• Overall Consequence Area for Personnel Injury
  • The largest area of the three possible personnel injury areas.
• FINAL Component Consequence Area
  • The larger area between component damage and overall personnel injury areas.
• Percentage of Toxics in Process Fluid (wt%)
  • The overall amount of toxics found within the process fluid.

Level 2

A level 2 analysis contains information that must be found by the user, thus not all information is found within the standard. The user is required to find or create their own thermodynamic and cloud dispersion model software to handle any process fluid with multiple phases. ReliaSoft RBI software does not perform Level 2 Consequence Analysis.

Atmospheric Storage Tanks

These are assumed to only hold oil.