Control Utility Systems Connected to a Process

Image © EPSC


When utility systems are temporarily connected with a flexible hose to a process, hazardous substances can flow back into the utility system.

When Important

  • During inerting, cleaning and unplugging operational equipment using utilities.
  • When taking a sample a utility is needed to purge a system.

Challenges in the Field

  • Lack of knowledge.
  • Easy availability of utility stations & hoses.
  • Hazard studies did not identify the hazard.

Options to Get it Right

  • Awareness of the hazard that utilities can be contaminated with process gasses or liquids.
  • Understand the pressures in the systems and how they can deviate during operation.
  • Define suitable safeguards against backflow, at least one non-return valve must be present.
  • Remove the utility hoses from the process directly when the task is completed.
  • Ensure that the hoses applied have the same pressure rating and chemical compatibility as the process when used in normal operation.
  • Evaluate backflow during MoC and HAZOP studies when fixed connections exist between utilities and process units.

This page only summarises the guidance – refer to the EPSC website for further information.

For more information on our Process Safety Fundamentals (or other) playing cards please contact us.