Construction of a water meter (water meter)

Turbine water meter - the axis of rotation of the turbine of the flow meter is parallel to the axis of the pipeline on which it is installed. Turbine water meters are manufactured with nominal diameters from DN40 and are used to measure large flows of hot or cold water. To reduce the impact of the water flow on the turbine blades of the flow meter, a flow former is installed in front of it, which directs the flow onto the blades at a certain angle.

Woltmann water meter - the axis of rotation of the turbine of the Woltmann flow meter is perpendicular to the axis of the pipeline on which it is installed. They are usually made with nominal sizes no larger than DN50 and are used to measure small flows of cold or hot water.

Multi-jet water meter

Multi-jet water meter - before reaching the turbine, the flow is divided into several streams, ensuring uniform water flow onto the working wheel. The measurement error, which depends on the turbulence of the flow, is much lower than in single-jet water meters with similar characteristics. The dimensions of multi-jet water meters are slightly larger than those of single-jet analogues.

Single-jet water meter

Single-jet water meter - does not have a device that forms the flow of water before it enters the turbine.

Wet-type water meter - differs in that the measuring mechanism is flushed with the flow of water passing through the flow meter. Wet-type flow meters are sensitive to mechanical impurities in the water, so they are recommended for use in clean environments.

Dry-dial water meter - the measuring mechanism does not come into contact with the water, and the rotation from the turbine to the measuring mechanism is transmitted using magnetic couplings. The body of dry-dial water meters is protected from the influence of magnetic fields, and the measuring mechanism can be removed without emptying the pipeline. Dry-dial water meters can usually be equipped with a reed switch sensor with a pulse output for connection to a computer or for use in automation schemes. The price of a dry-dial water meter is usually higher than that of equivalent wet-type flow meters.

Combined water meter — used in systems with a wide range of flow rates. Structurally, the combined water meter consists of two mechanical water meters in one housing. The water meters are selected so that the maximum flow rate for the smaller meter is slightly greater than the minimum flow rate for the larger meter. Switching from one meter to another occurs automatically when the water velocity reaches a certain value. The amount of water consumed is determined as the sum of the readings of the two meters. The combined water meter helps to eliminate one of the main drawbacks of mechanical water meters - a small range of flow rate measurement.

Advantages of mechanical water meters:

Easy to service
No need for electrical power
Relatively low cost compared to similar water meters of other types
The design of some allows for installation in rooms filled with water
Some mechanical water meters can measure the flow rate of heavily polluted liquids

Disadvantages of mechanical water meters:

Small range of flow rate measurement
High pressure loss
Lack of instantaneous flow rate indication
Presence of moving parts in the flow section
The need to install a mesh filter before the water meter
Short service life and low measurement accuracy

Ultrasonic water meter

The design of an ultrasonic water meter includes a flow metering section, a calculator, and two or four pulse transmitters located at an angle to the axis of the pipeline. The flow metering section is made of brass, bronze, or stainless steel.

Advantages of ultrasonic water meters:

High precision measurement of clean water flow
Wide range of flow measurement
Do not introduce significant hydraulic resistance
No moving parts in the flow section
Instantaneous water flow indication
Archiving of water consumption data
Long service life
Meter verification for large diameters can be performed without removing from the pipeline

Disadvantages of ultrasonic water meters:

External or autonomous power source is required
The presence of air bubbles in the water significantly affects the measurement accuracy
High requirements for the premises in which they are installed

Electromagnetic water meter

The construction of an electromagnetic water meter includes a calculator, inductive coils, EDS measuring electrodes, and a flow measurement section made of non-magnetic and non-conductive material such as PTFE or polyethylene.

Advantages of electromagnetic water meters:

Measure the flow of clean water with high accuracy
Have a wide range of flow measurement
Do not introduce significant hydraulic resistance
Do not have moving or protruding parts in the flow section
Long service life
Indicate instantaneous water flow rate
Archive data on water consumption
Do not affected by the presence of contaminants in the water that do not change its electrical conductivity

Disadvantages of electromagnetic water meters:

Require an external power source
Have high demands for installation quality
Have high demands for installation premises
High sensitivity to flow turbulence and non-uniform velocity distribution in the meter section
The accumulation of metal debris retained by the magnetic field is possible in the flow section of the meter
Unsuitable for measuring the flow of liquids with low electrical conductivity, such as alcohols and petroleum products