This European Standard describes the specific functional recommendations for steel pipelines in addition to the general functional recommendations of EN 12007-1 for maximum operating pressures up to and including 16 bar. This European Standard specifies common basic principles for gas supply systems. Users of this European Standard should be aware that more detailed national standards and/or codes of practice can exist 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.