Monitor an Open Drain

Image © EPSC


Unintended product release can occur during draining from a storage tank or other equipment to atmosphere.

When Important

  • When draining water from a tank that contains hydrocarbons to a sewer.
  • When removing liquid from process equipment.

Challenges in the Field

  • Distracted by other things that need attention.
  • Long draining time.
  • Bad weather.
  • Under estimation of the potential consequence of the product being released.
  • Drain valve does not fully close.

Options to Get it Right

  • Identify the critical draining operations on site.
  • Limit drain size (typical to 1 inch or 25 mm) to limit the release rate of the hazardous chemical.
  • Spring Loaded valves can help to assure that an operator remains present when drain time is short.
  • Understand the draining time necessary when starting the draining process.
  • Ensure the drain-valve can be closed from a safe location.
  • Avoid doing something else while monitoring a draining task.
  • In a critical situation, first stop the draining process before leaving the drain.
  • Stop draining during shift handover.

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.