Part 1 of this European standard applies to mechanical filters for drinking water installations inside buildings, of nominal size from DN 15 to DN 100, minimum nominal pressure PN10, particle rating of 80 to 150 µm, and minimum design temperature of 30°C. It specifies requirements relating to the construction and mode of operation of filters and describes relevant methods of testing. It only concerns units which are permanently connected to the mains supply at the point of entry into the building.