Measurement of water flow in fully charged closed conduits - Meters for cold potable water and hot water - Part 3: Test methods and equipment

2Scope / Description

This part of GB/T 778 specifies test methods and test equipment for determining the main characteristics of water meters. This part of GB/T 778 applies to water meters with a maximum allowable working pressure (MAP) greater than or equal to 1 MPa (10 bar), a nominal pipe diameter DN ≥500 of 0.6 MPa (6 bar), and a maximum allowable working temperature (MAT ) Various cold drinking water meters and hot water meters with a rating of 30°C for cold drinking water and a hot water meter up to 180°C. This part of GB/T 778 also applies to water meters based on electrical or electronic principles and based on mechanical principles with electronic devices for measuring the actual volume flow of drinking cold water and hot water. For water meters with a common flow rate of less than 160 m/h, when conducting durability tests or performance tests under various influencing quantities, in order to adapt to the conditions of each test laboratory, the test outline can stipulate modified reference conditions. Note: If national regulations are involved, the national regulations are higher than the provisions of this part of GB/T 778.