1. The first type of anti-drip water meter is a magnetic pressure sensitive element composed of a magnetic material as an anti-drip mechanism, and is placed in the surface of the water inlet of the water meter. When the tap water flows outward in the form of dripping, The magnetic pressure sensitive mechanism intermittently supplies water to the water meter to meter the water meter. This method can make the water meter start flow less than 0.5 L/H, but the water meter of this structure uses the magnetic column as the piston. Most afraid of impurities such as rust, iron and mud sand in the water, the magnetic column is most easily trapped by impurities in the water and no longer has the function of preventing dripping;
2. The second type of anti-drip water meter uses a small tube or a small hole to introduce a small amount of tap water to the impeller box of the water meter, and sprays the impeller of the watch core to concentrate the water kinetic energy of the minute flow at a point to push the impeller. In order to rotate the impeller to achieve the purpose of micro flow metering, the water meter in this way can achieve a starting flow rate of 2 L/H, but the water meter of this structure concentrates the water meter in one place, so that It will cause more metering of the water meter, which will cause the water meter to generate a large potential due to the unstable water pressure of the water pipe network (that is, when the user closes the faucet completely without water, the water meter is unstable due to the water pressure of the pipe network). The phenomenon of idling), this kind of sneak is generally up to 192 liters / day (one month, even if you do not use water, you will vacate 5 ~ 6m & sup3; tap water), causing users to pay water fees, resulting in user complaints and refused to pay water The phenomenon of fees, another defect of this structure is that it is easily blocked and stuck by mud and sand, after a period of time (usually three to five months), it loses its anti-drip effect;
3. The third type is a diaphragm integral type anti-drip water meter. It is another cavity at the bottom of the case of the ordinary water meter. The upper structure is still the same as the ordinary water meter, and a soft diaphragm is used to seal the bottom. The body is connected to the water outlet of the water case, and there is a special anti-drip mechanism in the water outlet. When the tap water leaks out in the form of dripping, the anti-drip mechanism still closes the water outlet of the water meter, and the water dripping outward is actually a water meter. The water in the bottom chamber, when the water in the bottom chamber (the volume is 36 ml) is dripped, the anti-drip mechanism is opened, thereby replenishing the discharged water to the bottom chamber, and the water in the chamber is replenished. After the completion, the anti-drip mechanism seals the water meter outlet under the action of the spring, and enters the next cycle. The process of opening the water to the bottom cavity in the anti-drip mechanism is a process greater than the flow rate of the water meter, so the water meter is Can be metered.