Because the stability and durability of the working performance of the water meter under the common flow are the best, which is more in line with the design requirements. If the water pipe has a margin considering the future water capacity, the water meter can be selected with a lower caliber specification. If the flow of the pipe with the diameter of 200mm is insufficient, the water meter with the diameter of 150mm can be installed. When the flow increases to the normal flow of the pipe with the diameter of 200mm in the future, the water meter with the same diameter can be replaced. When large water consuming industrial users choose water meters, they can choose one large-diameter water meter or several relatively small-diameter water meters in parallel. In this way, they can repair or replace individual water meters without affecting the normal water supply of users.
2. Select water meter indication type
Generally, it is of character wheel type, with clear reading and convenient reading. However, some people think that it is better to install the pointer type when it is not possible to read the meter in close distance, because this type can judge the reading according to the geometric angle pointed by the pointer without seeing the value on the scale cylinder grid. In recent years, the liquid sealed counter is popular because it overcomes the disadvantage that the reading of the general counter is hindered by the dirt and rust in the water for a long time. The readings of remote water meters and prepaid water meters are displayed by electronic devices or collected and transmitted by centralized readers, but their base meter readings should still be retained for comparison in case of problems with the copied electronic devices.
3. Consider the convenience of installation and maintenance of the water meter
This should be especially considered for large-diameter water meters. Therefore, the water meter (such as detachable water meter) that can be installed, replaced or maintained without water supply can meet these requirements. The installation length and connection mode of water meters are also factors to be considered. Although the requirements in this regard have been specified in Table 1 and table 2 of the national standard GB / t778.1-1996, the installation length and connection mode of water meters manufactured according to this standard are the same. However, in recent years, some new water meters (including prepaid smart water meters) are not manufactured according to national standards, but according to enterprise standards, which may be different.
4. Considering water quality adaptability
Due to various reasons, the water quality flowing through the water meter and interrupted in many occasions is not as clean and ideal as that in the water outlet plant, and sometimes there are some impurities (such as rust, sand, hemp, etc.). In this case, in addition to considering the installation of some filters and other measures in the pipeline design of the water meter, the water meter or flowmeter that can adapt to such water quality needs to be considered.