External Inspections

Energinet regularly performs external inspections of our gas transmission pipelines.

Inspections from the air

Seven times annually, specialists from Energinet inspect the transmission network from the air, either from an altitude of 100 meters (five times a year) or 20-25 meters (twice a year).

Inspections by car

Five times a year, Energinet specialists inspect our pipelines by car. The inspection includes monitoring for gas leaks.


Energinet technicians check to make sure the pipeline is not compromised by construction works or any other activity in its vicinity.

Inspections on foot

Four times a year, Energinet technicians inspect selected segments of our pipeline by foot.
The survey checks: 

Visibility of gas pipeline markers 
That the pipeline is free and clear of plants with deep growing root systems. 
Construction works without a permit.
Housing developments – or other undesirable activities – in proximity of the pipelines. 
 For traces of gas that may not register in our regular preventive safety inspection. 

Energinet generates a report based on the inspection to assess whether repair work is needed.

Inspections at sea

Energinet occasionally deploys mini submarines and divers when we conduct surveys at sea. Our specialists check the surface of the pipeline and make sure that the pipeline is not structurally compromised, that the base has not been washed away and that the pipeline remains well-anchored to the sea floor.

Visual inspection by divers is an important part of monitoring Energinet’s gas transmission pipelines.

Special vessel

Together with our external suppliers, Energinet surveys the pipelines in Lillebælt and Storebælt every fourth year. Our surveys are conducted from a specially designed Remote Operated Vehicle (ROV) and we measure the position of the pipeline by deploying mini submarines or use divers for visual inspections when required by the natural conditions. 


The underwater pipelines are made of steel with a wall thickness of at least 12 mm and a diameter of 76 cm.




We survey Energinet's pipelines on land from the air, by car and on foot, and we survey Energinet's submarine pipelines by deploying mini submarines and divers.