The test methods and properties of sealants used to reseal threaded joints of metallic gas pipework in buildings operated at a maximum allowed operating pressure of 100 mbar are defined in this Standard. NOTE: Gas pipework in buildings is in accordance with EN 1775 the pipework between the point of delivery and the inlet connection to the gas appliance. Applicable to sealants for threaded joints of metallic gas pipework, in buildings, carrying fuel gases of the 1st family (town gas), 2nd family (natural gas), and 3rd family (liquefied petroleum gases in the liquid state. Sealing materials for the installation of metallic threaded joints are specified in EN 751.