Dear Daniele, here is the map and properties of gas pipelines in Spain & Portugal: http://www.theodora.com/pipelines/spain_and_portugal_pipelines.html

However, LNG terminals are more important for gas delivery to Spain; see map here: https://www.ngva.eu/lng-blue-corridors-the-right-solution-for-a-more-economical-long-distance-road-transport

Dear Yuri, thanks for your reply! Howevr, do you know if I can get this as a shapefile?

Regards.

No idea of what is a shapefile and where can you get it. As for me, information with a map is sufficient. Then special programs can work with jpeg file to edit it, or you can draw a picture on your own based on these data.

I'll keep trying! Thank you for your attention, Yuri :) best regards!