This standard specifies the general recommendations for the design, construction, testing, commissioning, operation and maintenance of installation pipework, that is the pipework between the point of delivery of the gas and the inlet connection to the gas appliance. This standard specifies common basic principles for gas installation pipework. This standard is intended to be applied in association with national standards and/or codes of practice setting out the above mentioned basic principles. This standard is applicable to new installation pipework as well as to replacements of, or extensions to, existing installation pipework. For more information on gas pressure regulating installations, reference should be made to ÖNORM EN 12279. For more information on gas metering systems, reference should be made to ÖNORM EN 1776.