When water is not used, the water meter will turn.

When the newly installed water meter or water meter is moved out, the water in the pipeline is emptied, and the air will "take advantage of it"; When the water supply is resumed, the water flow presses the air in the pipeline to each blind end of the indoor pipeline to form "compressed air" until the air pressure and water pressure reach a balance. There is an interface between gas and water, and the pressure difference on both sides of the interface is zero.

When the water pressure changes, a certain pressure difference is formed on both sides of the interface, and the gas-water balance is destroyed. In order to make up for this pressure difference and achieve a new balance, it is necessary to change the air pressure accordingly, so that the air volume expands or contracts, thus promoting the flow of tap water in the pipeline "connecting device", and thus the phenomenon of "water meter idling" occurs.

Extended data

Specific phenomena and reasons of water meter idling;

Phenomenon 1: only forward rotation, the pointer rotates faster and more evenly;

Cause: Water leakage is generally caused by the damage of pipes and water facilities behind the water meter, and the water leakage point is easy to determine.

Phenomenon 2: the forward rotation speed of the pointer is slow, or the pointer rotates forward first and then reverses, but the forward rotation degree is greater than the reverse rotation degree;

Reason: Generally, it is caused by water seepage when the water pressure in the pipeline fluctuates due to improper installation of pipelines and fittings or sand holes on them. In this case, it is difficult to find the water leakage point.

Phenomenon 3: Under normal circumstances, the pointer does not rotate, but nearby users (the same supervisor) rotate when using water;

Reason: Generally, because the diameter of the main pipe is small or the adjacent water meters are close, there are not enough straight pipe sections before and after the water meters; Or there's a blind pipe behind the desk that can't be discharged. When other users use water, the water flow speed is high, which causes the fluctuation of water pressure or air pressure in the pipeline and drives the impeller of the water meter to rotate. There is generally no water leakage point.