How To Compare And Select Rotary Vane Wheel Water Meters And Volumetric Water Meters

The water meter records the flow of water flowing through a closed pipe. It is an integrative velocity flow meter. The principle is to use the mechanical action of the volume chamber of the movable wall or the water flow to push the movable element such as the turbine to rotate to continuously determine the water flow. Water meters have the characteristics of simple structure, wide range, convenient use, and low cost. Today, when water resources are becoming increasingly scarce, water-saving work has been paid attention to by governments around the world. As a measuring instrument and control method in the water-saving link, water meters can quickly development of.

   Classification of civil water meters

    There are many types of water meters, and there are many classification methods. Generally, there are the following classification methods:

A. According to its principle of action, it can be divided into two categories:

Measured water meter: also known as a volumetric water meter to measure the actual volume of the water meter;

Inference water meter: also known as speed water meter, a water meter that measures the speed of water flow and indirectly measures the amount of water flowing through it.

Volumetric water meters are mainly rotary piston water meters, which are widely used in the United States and the former Commonwealth countries. Its metering level is high, and its stability is good, but it has high water quality requirements and high product manufacturing costs;

There are many types of turbine water meters. Generally, there is an impeller inside, which is rotated and measured by the impact of water flow. It is widely used in most countries. The structure is simple, the production technology is good, and the cost is low.

 B.According to its counter type, it can be divided into two categories:

Wet water meter: the counter is immersed in water, the starting flow is small, and the anti-fouling performance is poor;

Dry water meter: the counter is isolated from the water, the starting flow is small, and the reading is clear;

C. According to the reading indication mode, it can be divided into pointer type, word wheel type, pointer and word wheel combined type; rotary wing water meter is divided into multi-stream water meter and single-stream water meter according to the inlet structure type; according to the installation method, it is divided into Horizontal type, vertical type; according to the operating temperature, it is divided into cold water meter, hot water meter, etc.

D. Residential water meters are generally below DN40. DN15 and DN20 are suitable for single-household water measurement, and DN25, DM32, and DN40 are suitable for multi-household water measurement.

The working principle and characteristics of commonly used water meters

A.The working principle of rotary vane wheel water meter:

  The working principle of the rotary-wing multi-stream water meter is that through the distribution of the impeller box, multiple streams of water enter the impeller from the water inlet of the impeller box, so that the axial impact force of the water flow on the impeller is balanced, and the impeller supporting part is reduced. Wear and tear, and increase the service life of the water meter from the structure. The product parts have a large matching gap between each other, so the water quality requirements are low, and it is obviously better than the volumetric water meter in use, which is convenient for water meter management and maintenance.

B.Characteristics of rotary vane wheel  water meter:

⑴ Vane wheel wet water meter

The counter of the wet water meter is immersed in water. Due to the buoyancy and wetting effect of the water on the transmission components, the water meter has high sensitivity, which is beneficial to the water supply company's water fee recovery. The wet water meter has a simple structure and low cost. It is currently the most widely used civil water meter. But its shortcomings are also obvious. Due to the water quality, the counter is easily polluted, scale deposits, and the reading is unclear. Especially for outdoor installation in the south, under photosynthesis, it is prone to moss and moisture, making it impossible to read meters. There are many complaints and disputes from residents, which are products that are phased out.

⑵Vane wheel dry water meter

The counter of the dry water meter is sealed from the water by a gear box, and the movement is transmitted through the coupling of two magnetic steels of the impeller and the central gear to achieve the purpose of counting and measuring. Its advantages are clear readings and easy to read water volume. The measurement accuracy of water meters can reach ISO4064 level B and C. It is widely used in Germany, Italy, France, Northern Europe, the Middle East, Africa, and South America. It is currently the most widely used internationally. Water meter products account for about 70% of the total global meters. The advantage is that the requirements for water quality and water supply pipe network are not high, subsequent maintenance is simple and convenient, and the maintenance cost is low.

C.The working principle and characteristics of rotary piston water meter:

The rotary piston water meter uses the pressure difference between the two ends (water inlet and water outlet) of the water meter measurement chamber. The water flow entering the water inlet pushes the piston to rotate, squeezing the water in the metering chamber to the water outlet. Every time the piston rotates for one revolution, the water of a metering chamber volume is squeezed out of the water outlet, and at the same time, the fork is rotated for one revolution by the piston shaft to record the water consumption.

  The water consumption of a metering chamber volume is recorded every 1 revolution of the piston. This can be calculated by theory, and the friction coefficient of the parts in the metering chamber of the water meter is small, and the geometrical dimension accuracy is high. Therefore, the metering accuracy of the water meter is high and can reach ISO4064 C-level and D-level levels are very beneficial to water fee recovery. The disadvantage is that due to the small gap between the product parts, the movement of the piston along the metering chamber wall is a rolling and sliding process, and the gap between the piston in the metering chamber is only 0.02-0.1mm, which requires very high water quality. Therefore, impurities and fine sand will seriously affect the metering performance and service life of the water meter, and the manufacturing and maintenance costs are high.

  In summary, the multi-flow rotary wing water meter is better than the piston water meter. Customers can also purchase suitable water meters according to their needs.