Stored pressure: Corrosion coupon plug ejected from pressurized pipeline

  • Safety Flash
  • Published on 4 July 2016
  • Generated on 2 July 2025
  • IMCA SF 18/16
  • 1 minute read

The International Association of Oil and Gas Producers (IOGP) has published a safety alert regarding an incident in which a corrosion coupon plug was ejected from a pressurised pipeline. 

What happened?

The incident occurred during a ‘routine’ plug retrieval operation on a 28″ crude oil pipeline. The plug was ejected at high velocity from a 2″ access fitting on the pipeline. The pipeline was pressurised to 103 bar. There was a spillage of crude oil from the pipeline via the access fitting. There were no injuries.

Why did it happen? What were the causes?

Investigation revealed that the most likely cause was that the threads of the access fitting were worn down and unable to restrain the plug against 103 bar of pressure. The access fitting was nearly thirty years old and had been subject to over 140 coupon retrieval and installation cycles.

Further information is available at safetyzone.iogp.org/SafetyAlerts/alerts/Detail.asp?alert_id=273

Latest Safety Flashes:

NTSB: Vessel crane contact with shore-side crane

The National Transportation Safety Board of the United States (NTSB) has published a report and an investigation.

Read more
Dropped pallet during forklift operation

A pallet containing a load weighing 500kg dropped off a flatbed truck in close proximity to a delivery driver.

Read more
Dropped object hazard: access hatch to the communication dome

During a routine scheduled safety inspection of the main mast, it was discovered that the access hatch to one of the communication domes had fallen off.

Read more
Lock out/Tag out and unauthorised electrical connections/disconnections
Read more
MAIB: Is your Lead-Acid battery safe?

The UK Marine Accident Investigation Branch has published Safety Digest 1/2025, consisting of lessons from recent Marine Accident Reports.

Read more

IMCA Safety Flashes summarise key safety matters and incidents, allowing lessons to be more easily learnt for the benefit of the entire offshore industry.

The effectiveness of the IMCA Safety Flash system depends on the industry sharing information and so avoiding repeat incidents. Incidents are classified according to IOGP's Life Saving Rules.

All information is anonymised or sanitised, as appropriate, and warnings for graphic content included where possible.

IMCA makes every effort to ensure both the accuracy and reliability of the information shared, but is not be liable for any guidance and/or recommendation and/or statement herein contained.

The information contained in this document does not fulfil or replace any individual's or Member's legal, regulatory or other duties or obligations in respect of their operations. Individuals and Members remain solely responsible for the safe, lawful and proper conduct of their operations.

Share your safety incidents with IMCA online. Sign-up to receive Safety Flashes straight to your email.