Inline Inspection

Energinet regularly conducts inline inspections of our gas transmission pipelines, so called "pigging", as a preventive measure that protects our system against damages. Our inspections are carefully planned.

A pig unlike any other

Energinet conducts its inspections with a “pig”, which is a device that, propelled by the pressure in the pipes, travels through our transmission pipelines and measures the structural integrity of our system.

Two types 

We generally conduct two types of “pigging” inspections:

1) Caliper pigging, which locates dents and cracks and cleans our pipelines.
2) Intelligent pigging, which scans our pipelines for signs of corrosion or other types of damage to the surface of the pipeline, internally and externally.

Insertion of intelligent pig into our pipeline (left) and a caliper pig with a gauge plate (right)

Insertion of intelligent pig into our pipeline (left) and caliper pig with gauge plate (right).

Scheduled Inspections

Energinet conducts caliper and intelligent pigging inspections of the subsea gas transmission pipelines in Storebælt and Lillebælt every fourth year. Every 10th year, Energinet performs a combined caliper and intelligent pigging inspection of all onshore pipelines.

Visual inspections

Energinet analyses the data collected from the pigging inspections. Based on the produced reports, Energinet may decide to excavate a particular segment of our pipeline if we conclude that additional visual inspection is required to assess if any repair work is needed.

Inspection types

Energinet conducts two types of “pigging” inspections:

1) Caliper pigging; and
2) Intelligent pigging