Guide for the prevention of water meter rotation
With the development of urban housing construction, the urban water supply meter has gradually changed from the original general meter and unit meter water supply method to a centralized management method of one household and one meter for the water distributor. The phenomenon of rotation measurement.
Type of water meter rotation
Rotation caused by fluctuations in the pipe network
▌The municipal water supply part of the water meter rotates in a large area
In recent years, with the increase of secondary water supply facilities, many high-rise residential communities and nearby municipal water users have seen large-scale water meter rotation. After investigation, some communities use non-negative pressure water supply equipment. When the pump is started, it is equivalent to pumping water directly from the municipal pipeline, causing pressure fluctuations in the municipal pipeline network, which affects the measurement of the surrounding water meters directly supplied to users.
▌Small rotation of the water meter of the Municipal Water Supply Department
For the self-rotation of the direct-supply part of the water meter caused by the pressure fluctuation of the municipal pipe network, caused by the frequent opening of the high-flow water inlet of the secondary water supply facility. After the network pressure fluctuation is transmitted to the water meter, the water meter rotation problem is solved.
However, because the check valve will cause head loss, a check valve should be installed under the premise of ensuring that the user's normal water consumption is not affected.
▌Insufficient distance between water meter pipes causes the water meter to rotate
At present, most household meters are installed in the same water meter well. The pipes of the splitter are too thin, the distance between the water meters is too small, and the front and rear straight pipes are not long enough. Negative pressure is formed near the splitter of the water user, the water pressure distribution balance between the water meters is broken, and the remaining water after the water meter of the other users flows back into the splitter to form a water meter inversion. When the water is stopped, the pressure in front of the water meter of the other users rises, and the meter is compressed. Afterwards, the liquid forms a positive rotation, and finally forms the water meter rotation. For the existing water meter rotation, it can be solved by installing a check valve in front of the water meter. For newly installed users, it can be prevented by increasing the pipe diameter of the splitter and leaving a sufficient distance between the left and right water meters.
Rotation of the water meter due to the presence of air in the pipe
▌Pressure is part of the water meter rotation
The large-area water meter rotation that exists in the pressurized part is mainly caused by the gas in the pressurized part of the pipeline. The pressure fluctuates during the operation of the pressurized pump, and the compressed gas can be caused by installing an exhaust valve at the end of the zone. The valve discharges the gas in the pipeline to solve it.
▌The rotation of the water meter is caused by the presence of gas in the pipeline in the user's home
Regarding the rotation of individual users' water meters in the community, after investigation, it is found that most of them are caused by the long time no water is used, and the gas in the pipeline cannot be discharged. The gas in the pipeline can be discharged by opening the high faucet or closing the water meter valve. Way to solve it.
▌Water meter rotation caused by pipeline laying
In the marketing work, it was discovered that some of the water meters could not be resolved by the discharge of gas. The investigation found that there was a dead water pipe at the highest point of the user's pipe. There was gas in the dead water pipe, and the gas could not be discharged by turning on the faucet. For this kind of situation, the user can eliminate the dead water pipe or install a check valve in front of the water meter to solve it.
The solution to the rotation of the water meter
▌Install a check valve
The rotation of the water meter is mainly caused by pressure fluctuations and compression of the airbag. You can consider installing a check valve. The check valve can prevent the backflow of water. In this way, when the pressure increases, the airbag is compressed and the water meter rotates; when the pressure decreases, the check valve is automatically closed and the water meter does not rotate; when the pressure rises again, as long as the pressure is not higher than the pressure in the check valve, The water meter will not turn again. The rotation of the water meter is mainly due to the reciprocating measurement of the water meter many times to accumulate a large amount of water. The installation of a check valve can reduce the frequency of the water meter rotation, and it can also solve the problem of water meter rotation caused by pressure fluctuations.
▌Construction strictly follows the drawings
According to the statistical analysis and processing results of the on-site investigation, the main reason for the self-rotation phenomenon of the water meter is the leakage of the indoor pipes and water appliances, and the main reason is the unreasonable installation of the indoor pipes, which leads to the generation of air bags in the indoor pipes. Therefore, in future work, Standardized construction and construction should be done according to the drawings, not "innovative" construction, and necessary exhaust facilities should be installed. In addition, the design depth of the pipeline should meet the requirements. In the design, the exhaust valve should be reasonably arranged according to the characteristics of the pipeline to remove the gas in the pipeline in time; when the newly installed pipeline or the newly installed household meter is connected to the water for the first time, the valve should be opened slowly, and the pipeline should be drained as much as possible. The air inside reduces the air content in the water.
▌Water meter and pipeline installation should be combined with the actual conditions
When installing new water meters and indoor pipelines, the pipelines should be laid upward along a certain slope to reduce pipeline bending points and breakpoints. The highest point of the pipeline should be designed on a frequently used faucet to reduce the occurrence of air bubbles in indoor pipelines. Chance. The water meter out-of-home renovation project should avoid the blind pipe in the house caused by the change of the water inlet direction in the user's home. If the blind pipe is located in a high position or is located in a protruding pipe section of the pipeline, it is easy to produce air bubbles. The blind pipe should be removed during construction. The water meter was unoccupied after leaving the house, and there was a lot of gas in the pipeline. It is recommended to investigate the user's situation when the water meter leaves the house. When the water meter is installed and accepted, close the rear valve of the user's water meter without occupants, and sign a contract with the user when the water meter leaves the house to explain the reason.
▌Install the exhaust valve
It can be seen from the statistical analysis that the main reason for the rotation of the water meter is still caused by gas, so you can consider installing an exhaust valve. However, due to the high price of the exhaust valve, and high requirements for installation location, piping layout, etc., at the same time, it is necessary to consider the loss of other facilities and equipment caused by the water discharged from the exhaust valve.
Such items as elevators, meter wells, indoor decoration, etc., will also add a certain amount of work to the maintenance and management of the pipe network, so unless necessary, install as few exhaust valves as possible. During the implementation of pipeline engineering,
If the burial depth allows, use the water point at the commanding height of the pipeline to reduce the exhaust valve, discharge the fire hydrant, or the user can achieve the function of exhausting the pipeline when using water.
In conclusion
The reasons for the rotation of the water meter can be summarized into two categories.
One is caused by the structure of the water meter itself. At present, most mechanical water meters are one-way measuring instruments, which results in different measurement values between the forward and backward directions, and the water meter rotates.
Second, the improper installation of the water meter is the cause of the rotation of the water meter.
Therefore, in the pipeline construction, the construction standards and construction specifications must be strictly implemented to eliminate the inducement of the water meter rotation caused by the unreasonable installation of the pipeline.