Turbine flowmeters are widely used in petrochemicals, organic liquids, inorganic liquids, liquefied gases, natural gas and fluids at low to middle temperature .Now it is widely used which is next to orifice plate flow meter.
(1) High accuracy
For liquids, it is generally ±0.25%~±0.5%, for gas turbine flow meter, it is generally ±1.5%, and the special special type is ±0.5%~1%. Turbine flowmeters are the relative high accurate flow meters comparing to other types flow meters.
(2) Good repeatability
Short-term repeatability is up to 0.05% to 0.2%. It can be used for custody transfer if users frequent calibrate the flow meters.
(3) Wide measuring range
For large size turbine sensor, the turn down ratio can be 40:1~10:1, and for small size sensor tube, it can be 6:1 or 5:1.
(4) Output pulse frequency signal
Suitable for total metering and computer connection, no zero drift, strong anti-interference ability. A very high frequency signal (3~4Hz) is obtained from the turbine sensor, and the signal resolution is strong.
(5) Suitable for high pressure measurement
The meter body is easy to make a high-pressure type meter.
(6) There are many types of structures, which can adapt to the needs of various measurement purpose, such as can be made into thread or flange type , or even made into tri-clamp type for hygienic purpose.
Disadvantages of turbine flow meters
(1) It is difficult to maintain the calibration characteristics for a long time, and it is necessary to periodically re-calibrate. For non-lubricating liquids, when the liquid contains suspended solids or is corrosive, it is easy to cause problems such as bearing wear and rotor stuck. In special working conditions, wear-resistant hard alloy shafts and bearings are required. When it is for custody transfer and high accuracy is needed, it is best to have on-site calibration equipment that can be calibrated regularly to maintain its accuracy
(2) Not applicable to higher viscosity fluids flow measurement. As the viscosity increases, the flow meter measurement lower limit increases, the measurement range decreases, and the linearity is poor.
(3) Fluid properties (density, viscosity) have a great influence on the flow meter performance. Gas turbine flow meters are easily affected by the gas density, while liquid turbine flow meters are sensitive to liquid changes in viscosity. Since density and viscosity are closely related to temperature and pressure, in the case of large fluctuations in temperature and pressure in the field, compensation measures should be taken to maintain the high accuracy.
(4) The flowmeter is greatly affected by the distortion of the flow velocity distribution and the swirling flow. Long straight pipe sections are required to be installed upstream and downstream of the turbine flow sensor.
(5)Turbine flow meter can only measure clean fluids, and filters are normally needed when installing the sensor.
(6) The small-size (2" or less) meter flow characteristics are seriously affected by physical properties, and the flow meter performance is difficult to improve for small size sensor.
(7)Turbine flowmeter installation
Normally turbine flow meter has flange, thread, clamp-on connections, and the fluids direction should be the same as the arrow on the meter body. The liquid turbine flow sensor can be installed horizontally and vertically, and the fluid direction must be upward when installed vertically. The liquid should be filled with tubing and must be free of air bubbles. The inner wall of the straight pipe section should be smooth and clean, free of defects such as dents, scale and peeling.
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