The Use of Liquid Turbine Flow Meter and the Requirements for the Installation Environment

Ⅰ. The measurement of liquid turbine flow meters

The ideal measurement environment is a strong guarantee for the normal operation of the flow meter, but in many cases, the complex environment on site will also affect the accurate measurement of the turbine type flow meter. The flow meter is divided into the velocity flow meter and the positive displacement flow meter according to the different measurement principles. The measurement methods of different principles have very different installation requirements.

Ⅱ. The factors influencing the accuracy of liquid turbine flow meters

The velocity liquid turbine flow meters generally require a long enough straight pipe section to achieve the purpose of full pipe and stable flow rate. However, general positive displacement flow meters, such as oval gear flow meters, which do not have too many requirements for straight pipe sections. If the instrument manual does not specify the instrument in detail, and the installation location and flow direction, maintenance space, installation direction and other requirements and their influence should be considered.

1. The safety of turbine flow meters

Safety is the first factor to consider when selecting a turbine flow meter. For example, the requirement of explosion-proof performance is applied in explosive and hazardous environment, and the instrument is selected according to atmosphere adaptability, explosive mixture classification, type of protective electrical equipment, and other safety rules or standards.

2. Compressive strength of the turbine flow meter

It is required that the shell of the turbine type flow meter should be able to withstand the pressure strength test for 5 minutes at a test pressure of 1.5 times the maximum working pressure without damage or air leakage.

3. The ambient temperature of the turbine flow meter

The electronic components of the turbine flow meter and the flow detection part of some instruments will be affected by changes in the ambient temperature.

4. The environmental humidity of the turbine flow meter

High humidity will accelerate atmospheric corrosion and electrolytic corrosion and reduce electrical insulation, and low humidity will easily induce static electricity. The environmental temperature of the turbine flow meter or the rapid change of the medium temperature can cause humidity problems. The user should anticipate the possible range of changes and verify whether it will cause problems in the operation of the selected instrument.

5. Electrical interference of the turbine flow meter

Power cables, motors and electrical switches all produce electromagnetic interference, which become the sources of errors. Therefore, users should prevent or reasonably and effectively ground or shield interference sources.

6. Pipeline vibration of the turbine flow meter

Some flow meters (such as vortex flow meters) are susceptible to vibration interference, so you should consider using the labeled pipeline as a reliable support design. Although the pulsation buffer can eliminate the influence of the pump and compressor, it should be installed away from vibration or pulsation.

7. The upstream and downstream pipe sections of the turbine flow meter and the requirements for straight pipe sections

Most velocity flow meters, including turbine flow meters, are more or less affected by the flow conditions at the inlet and must ensure a good distribution of flow velocity. The pipeline layout will introduce different types of flow disturbances, the most common ones are the distortion of the velocity profile and the vortex. The vortex is generally caused by two or more space elbows. These effects can be improved by using an upstream straight pipe section of an appropriate length or installing a rectifier to ensure the stability of the flow velocity of the measuring pipe section and the full pipe state.

8. The pipeline layout direction of the turbine flow meter

Some flow meters are installed horizontally or vertically, and there will be differences in measurement performance. For example, the vertical downward flow of the fluid brings extra force to the rotating components of the instrument, which will significantly affect the performance and impose linear or repeated destroy. The installation direction of the smart liquid turbine flow meter is generally horizontal. The installation direction of most meters is specified by the manufacturer and should be followed.