scope:

Specifies the technical charateristics, metrological characteristics, pressure loss and marking of meters for hot water. It applies to water meters which are self-contained integrating measuring instruments continuously determining the volume of water flowing throught them, employing a direct mechanical process involving the use of volumetric chambers with mobile walls ("volumetric" meters) or the action of the velocity of the water on a moving part ("velocity" meters). A magnetic coupling is considered as a direct mechanical process. It applies to hot-water meters having permanent flowrates which lie in the range 0,6 m3/h to 400 m3/h maximum admissible working pressures (MAP) of 10 bar to 40 bar and maximum admissible temperatures (MAT) corresponding to one of the following values: 70 °C, 90 °C, 130 °C and 180 °C.