This European Standard DIN EN 15001-1 specifies detailed functional requirements for the design, selection of materials, construction, inspection and testing of industrial gas installation pipework and assemblies with an operating pressure greater than 0,5 bar, and non-industrial gas installation pipework (residential and commercial) with an operating pressure greater than 5 bar in buildings, starting from the outlet of the network operator’s point of delivery up to the inlet connection to the gas appliance; normally the inlet isolation valve. This standard also covers the inlet connection to the gas appliance comprising of the pipework that does not fall within the scope of the appliance standard.