Gases of fluid group 1
Pipelines according to Article 3 Number 1.3 Letter a) First dash
Exception: Unstable gases (e.g. acetylene and ethylene) belonging to Categories I and II, must be included in Category III
Gases of fluid group 2
Pipelines according to Article 3 Number 1.3 Letter a) Second dash
Exception: Liquids and steam, at temperatures > 350 °C belonging to Category II must be included in Category III.
Liquids of fluid group 1
Pipelines according to Article 3 Number 1.3 Letter b) First dash
Liquids of fluid group 2
Pipelines according to Article 3 Number 1.3 Letter b) Second dash