The National Natural Gas Transmission System (NNGTS) consists of:
- The Main gas transmission pipeline and its branches
- The Compression Stations
- The Natural Gas Metering / Regulating Stations at Entry – Exit Points
- The Natural Gas Control and Dispatching Centers at Patima Elefsinas and at Nea Mesimvria Thessaloniki
- The Remote Control and Communication System
- The Operation and Maintenance Centers of South Greece, Central Greece, North Greece and North-East Greece.