scope:

This European Standard is applicable to pipelines with a maximum operating pressure (MOP) over 16 bar for the carriage of processed, non-toxic and non-corrosive natural gas according to EN ISO 13686 in onland gas supply systems, where: - pipeline elements are made of unalloyed or low-alloyed carbon steel; - pipeline elements are joined by welds, flanges or mechanical couplings; - the pipeline is not located within commercial or industrial premises as an integral part of the industrial process on these premises except for any pipelines and facilities supplying such premises; - the design temperature of the system is between -40 °C and 120 °C inclusive. The standard applies to onshore pipeline systems from the point where the pipeline first crosses what is normally accepted as battery limit between on and offshore, e.g.: - first isolation valve; - the base of steep sea shelf; - above the high water/low water mark onto mainland; - an island. The pipeline standard also applies to a pipeline system with a starting point onshore, also when parts of the pipeline system on the mainland subsequently cross fjords, lakes etc. This European Standard does not apply to existing pipelines, in use prior to the publication of this European Standard, nor to modifications to existing pipelines. Gas supply systems covered by this European Standard begin after the gas producer's metering station. The functional demarcation of the pipeline system within a plant area will be determined from case to case. Generally speaking, this will be directly after the first isolating valve of the installation. This standard also describes the mechanical requirements for pipework in stations with a maximum operating pressure greater than 16 bar. Welding requirements are described in a special application standard on welding for gas supply systems EN 12732. Functional requirements for stations are given in: EN 1776, Gas supply systems - Natural gas measuring stations - Functional requirements EN 1918-5, Gas supply systems - Underground gas storage - Part 5: Functional recommendations for surface facilities EN 12186, Gas supply systems - Gas pressure regulating stations for transmission and distribution - Functional requirements EN 12583, Gas supply systems - Compressor stations - Functional requirements This European Standard specifies common basic principles for gas supply systems. Users of this European Standard should be aware that there may exist more detailed national standards and codes of practice in the CEN member countries. This European Standard is intended to be applied in association with these national standards and/or codes of practice setting out the above mentioned principles. In the event of conflicts in terms of more restrictive requirements in the national legislation/regulation with the requirements of this European Standard, the national legislation/regulation shall take precedence. Reference is made in this European Standard to relevant European and other recognized standards for products used to construct and operate gas supply systems. A schematic representation of pipelines for gas transmission is given in Figure 1.