Unplugging of Equipment

Image © EPSC


Unplugging might require opening of installations that can unexpectedly result in a release of hazardous substances.

When Important

When process equipment is blocked, e.g. by fouling, polymer, corrosion, objects after maintenance etc.

Challenges in the Field

  • Unexpected severe flow restrictions.
  • No unplugging procedure or good options.
  • Not wanting to stop production.

Options to Get it Right

  • Consider to stop production before unplugging.
  • Do not start unplugging without an approved plan that includes a hazard analysis.
  • Understand the source and reason of plugging.
  • Understand the hazards while unplugged and have a mitigation plan for unexpected releases.
  • Understand that instrumentation might give misreading or that safety valves do not operate properly.
  • Understand that opened equipment can still have pressurized hazardous material inside behind the plug.
  • Apply isolation and First Line Break principles in the unplugging procedure.
  • Do not use hazardous gas to blow out pipelines / equipment.

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.