This Part of DIN EN ISO 15874 specifies the characteristics of fittings for polypropylene (PP) piping systems intended to be used for hot and cold water installations within buildings for the conveyance of water, whether or not intended for human consumption (domestic systems) and for heating systems under design pressures and temperatures according to the class of application. This standard covers a range of service conditions (application classes) and design pressure classes. It also specifies the parameters for the test methods referred to in this standard. In conjunction with the other parts of DIN EN ISO 15874 it is applicable to fittings made from PP and to fittings made from other materials which are intended to be fitted to pipes conforming to DIN EN ISO 15874-3 for hot and cold water installations and whereby the joints conform to the requirements of DIN EN ISO 15874-5. It is also applicable to fittings made from alternative materials which when fitted to pipes conforming to Part 2, conform to the requirements of Part 5 of DIN EN ISO 15874. This standard is applicable to fittings of the following types: - socket fusion fittings - electrofusion fittings - mechanical fittings - fittings with incorporated inserts