Pipeline transport in order to avoid melting the frozen ground by hot petroleum which would result in sinking the pipeline in the ground. Maintenance of pipelines includes checking cathodic protection levels for the proper range, surveillance for construction, erosion, or leaks by foot, land vehicle, boat, or air, and running cleaning pigs, when there is anything carried in the pipeline that is corrosive. US pipeline maintenance rules are covered in Code of Federal Regulations(CFR) sections, 49 CFR 192 for natural gas pipelines, and 49 CFR 195 for petroleum liquid pipelines. In the US, onshore and offshore pipelines used to transport oil and
Pipeline transport not used for economic and ecological reasons. The typical annual loss of thermal energy through distribution is around 10%, as seen in Norway's district heating network. District heating pipelines are normally installed underground, with some exceptions. Within the system, heat storage may be installed to even out peak load demands. Heat is transferred into the central heating of the dwellings through heat exchangers at heat substations, without mixing of the fluids in either system. Bars in the Veltins-Arena, a major football ground in Gelsenkirchen, Germany, are interconnected by a long beer pipeline. In Randers city in Denmark, the so-called Thor