Little knowledge about water meters

1. Overview:

The water meter is used to measure the total one-way flow through the pipeline. It can be divided into hot water meter and normal temperature water meter (commonly referred to as water meter) according to its use; According to the measuring mechanism, it can be divided into rotor type water meter and horizontal spiral type water meter; According to the state of the meter head, it can be divided into wet water meter, liquid-sealed water meter and dry water meter.

2. Manufacturing method:

The manufacturing of water meters includes casting, cutting, assembly, calibration, inspection and packaging. Each process has a close relationship with the quality of the finished water meter, such as the shape of the water meter cavity (box), the quality of the inner surface, the shape and roughness of the measuring impeller, the spiral wing, the installation and calibration of the reduction mechanism and the indicator mechanism all affect the working accuracy of the water meter.

3. Purpose:

It is mainly used to measure the water consumption of factories, mines, enterprises and households.

4. Type:

(1) LXS rotor wet-type water meter: the rotor wet-type water meter is applicable to the measurement of the total one-way flow of small diameter pipes. For example, the household water consumption of pipes with diameter of 15mm and 20mm is used. The water meter is mainly composed of a shell, an impeller measuring mechanism, a reduction mechanism, and an indicator. It has the characteristics of simple structure.

(2) LXL horizontal spiral wing water meter: the horizontal spiral wing water meter is used to measure the total flow of large flow pipes. It is especially suitable for water consumption of main water supply pipes and large factories and mines. The main features are large circulation capacity, small size, compact structure, and easy to use and maintain.

(3) LXSY rotor type single-flow liquid seal water meter: the purpose is the same as LXS type. The difference in structure is that it closes the indicator mechanism with special liquid to prevent water from entering the indicator mechanism, and the water pressure acts on the rotor from one side of the rotor.

(4) LXSG rotor multi-stream (magnetic transmission) dry water meter: this meter has the purpose of LXS type, and has its unique structural features. The transmission of its impeller measuring mechanism and sealed indicator mechanism is realized by magnetic coupling. This indicator mechanism is isolated from water, preventing the indicator mechanism of wet water meter from being corroded and stained by water, so as to keep the indicator mechanism clear for a long time.

(5) Hot water meter: the structure of hot water meter is the same as that of normal temperature water meter, for example, the structure of LX-SR hot water meter is the same as that of LXS water meter. However, in order to meet the special needs of measuring hot water, all parts are made of heat-resistant materials.

(6) The electric measurement technology of non-electric quantity is applied to the water meter to form a remote water meter. In structure, the sensor is usually added behind the reducer and connected with the digital display instrument by cable.

5. Model and specification:

The model is expressed in letters and the specification in numbers, representing the nominal diameter. For example, LXL-80 refers to horizontal spiral wing water meter. The nominal diameter of 80 refers to the horizontal spiral wing water meter, and the nominal diameter is 80mm.

6. Performance index:

Main technical parameters of water meter include:

(1) Water temperature: This parameter specifies the maximum temperature of the water meter. Users should select appropriate models and specifications to meet their needs, otherwise, the water meter will not measure the total water flow accurately.

(2) Working pressure: specifies the maximum pressure of the measuring water body of the water meter. If the water pressure exceeds this limit, the water meter may be damaged or leaked.

(3) Flow coefficient: it includes nominal diameter, maximum flow, nominal flow, boundary flow, minimum flow and starting flow. Users can select nominal diameter and nominal flow according to practical needs. The initial flow reflects the sensitivity of the water meter.

(4) Indication error.

(5) External dimension and weight: the external dimension of the water meter includes various parameters to be understood during installation, such as length, width, height, connection thread, etc. In addition, the size and weight are related to packaging and transportation.

7. Inspection method:

The water meter is inspected according to the technical conditions of each manufacturer and GB/T778. Inspection items: appearance inspection (including overall dimensions, etc.), hydraulic test, indication error, flow measurement and accelerated wear test. The minimum number of water meters to be tested is 3, and the maximum number is 10 when it is necessary to increase the number of water meters to be tested.

8. Sign:

The arrow indicating the water flow direction and the nominal diameter of the water meter are projected on the case. Mark the trademark on the dial. Mark the measurement grade and manufacturing number under the cover.

9. Packaging, storage and transportation:

Each water meter shall have a separate small package to prevent collision during transportation and handling. The water meter shall be placed horizontally. The water meter is a kind of instrument, and the outer package should be marked with "up" and "handle with care". The water meter shall be stored in a dry place with an ambient temperature of 5-40 ℃ and no corrosive medium in the air.