Pipeline transport are usually buried. The oil is moved through the pipelines by pump stations along the pipeline. Natural gas (and similar gaseous fuels) are lightly pressurised into liquids known as Natural Gas Liquids (NGLs). Natural gas pipelines are constructed of carbon steel. Hydrogen pipeline transport is the transportation of hydrogen through a pipe. Pipelines conveying flammable or explosive material, such as natural gas or oil, pose special safety concerns and there have been various accidents. Pipelines can be the target of theft, vandalism, sabotage, or even terrorist attacks. In war, pipelines are often the target of military attacks. It is uncertain
Central Asia–Center gas pipeline system proposed to renovate existing systems and construct a new parallel pipeline to the western branch. On 12 May 2007, Vladimir Putin of Russia, Nursultan Nazarbayev of Kazakhstan and Gurbanguly Berdimuhamedow of Turkmenistan signed a memorandum for renovation and expansion of the western branch of the pipeline. On 20 December 2007, Russia, Turkmenistan and Kazakhstan finalized agreement on construction of the Caspian Coastal Pipeline parallel to the existing CAC-3 pipeline (known as Bekdash–Europe pipeline or Okarem–Beineu pipeline). Almost all Uzbek and Turkmen natural gas is delivered through the CAC pipeline system, mainly through the eastern branch due to location of production