This European Standard specifies requirements which enable a Transmission System Operator (TSO) to develop and implement a safety management system including an integrity management system specifically for pipelines.The SMS is applicable to infrastructure for the transmission of processed, non-toxic and non-corrosive natural gas according to EN ISO 13686 and injected bio methane, where:-the pipeline elements are made of unalloyed or low-alloyed carbon steel;-the pipeline elements are joined by welds, flanges or mechanical joints.NOTE 1In this standard, the term 'natural gas' includes injected bio methane or other non-conventional forms of natural gas, e.g. shale gas.Gas infrastructures for the transmission of natural gas covered by this standard are:-pipelines onshore including valve stations; -compressor stations;-measuring and pressure reduction stations.Gas distribution assets as well as LNG plants, terminals, underground storages are excluded from the scope of this standard.Occupational health and safety is excluded from this European standard because it is covered by national legislation and other European and/or international standards, e.g. OHSAS 18001.This European standard specifies requirements on a general level. The referenced documents given in Clause 2 'Normative references' give more detailed requirements for some of the assets listed above.This European Standard is intended to be applied in association with these national standards and/or codes of practice setting out the above-mentioned basic principles.In the event of conflicts in terms of more restrictive requirements in national legislation/regulation with the requirements of this standard, the national legislation/regulation takes precedence as illustrated in CEN/TR 13737 (all parts).NOTE 2CEN/TR 13737 (all parts) contains:-clarification of relevant legislation/regulations applicable in a country;-if appropriate, more restrictive national requirements;-national contact point for the latest information.