GB/T 778.4-2018 in English

《GB/T 778.4-2018饮用冷水水表和热水水表 第4部分：GB/T 778.1中未包含的非计量要求》由TC124（全国工业过程测量控制和自动化标准化技术委员会）归口，TC124SC1（全国工业过程测量控制和自动化标准化技术委员会温度、流量、机械量、物位、显示仪表、执行器和结构装置分会）执行，主管部门为中国机械工业联合会。

Scope

This part of GB/T 778 specifies the technical characteristic requirements for drinking cold water meters and hot water meters that measure the volume of cold water and hot water in closed full pipes and are equipped with cumulative flow indicating devices. This part applies to the following types of water meters: a) Maximum allowable pressure (MAP) is greater than or equal to 1 MPa (0.6 MPa for water meters with pipe nominal diameter DN≥500 mm); b) Drinking water meters with maximum allowable temperature (MAT) of 30 °C Cold water meters; c) Hot water meters with a maximum allowable temperature (MAT) of up to 180 °C by grade. This standard applies both to water meters based on the mechanical principle and to water meters based on the electrical or electronic principle and with electronic devices based on the mechanical principle for measuring the volume flow of cold and hot water for drinking. This section also applies to electronic auxiliary devices. Usually electronic auxiliaries are optional, but national or international regulations may determine that certain auxiliaries are mandatory depending on the usage of the water meter.