What are the disadvantages of turbine flowmeters?

This post was last edited by Wang Tianze on 2015-12-3 at 20:16. 1. It cannot maintain its calibration properties over the long term, and regular verification is required. For non-lubricating liquids, those containing suspended particles or abrasive substances, bearing wear and jamming become more pronounced, which limits their range of use. The situation improved significantly compared to graphite bearings after using cemented carbide shafts and bearings. For applications such as trade storage and transportation where high-accuracy measurements are required, it is best to have on-site calibration equipment available to perform regular calibrations in order to maintain their accuracy. 2. Although turbine flowmeters come in high-viscosity versions, the standard type is not suitable for media with high viscosity. An increase in the viscosity of the medium raises the lower measurement limit of the flow meter, reduces its range, and degrades its linearity. 3. Fluid properties (density, viscosity) have a significant impact on flow characteristics. Gas turbine flowmeters are susceptible to density effects, while liquid flowmeters are sensitive to changes in viscosity. Since both density and viscosity are closely related to temperature and pressure, and fluctuations in these parameters at the site are inevitable, corrective measures must be taken based on the degree of impact on accuracy in order to maintain measurement precision. 4. The flow characteristics of instruments with small diameters (φ50 and below) are greatly affected by the physical properties of the fluid, which makes it difficult to improve the performance of such instruments. 5. High cleanliness requirements are imposed on the medium being tested. The scope of its application is limited; although filters and similar devices can be installed to remove dirty substances, this also brings side effects such as increased pressure loss and higher maintenance costs. 6. The instruments are significantly affected by distortions in the incoming flow velocity distribution and rotational flows. A longer straight pipe section is required upstream and downstream of the sensor; if installation space is limited, a flow regulator (straightener) can be installed to reduce the length of the straight pipe section.

Significantly affected by pressure loss, cavitation, and vibration in pipelines

1. It cannot maintain its calibration properties over the long term and requires regular calibration. 2. Although turbine flowmeters come in high-viscosity versions, the standard type is not suitable for media with high viscosity. 3. Fluid properties (density, viscosity) have a significant impact on flow characteristics. 4. The instruments are significantly affected by distortions in the incoming flow velocity distribution and rotational flows. 5. High requirements are placed on the cleanliness of the medium being tested. 6. The flow characteristics of instruments with small diameters (φ50 and below) are greatly affected by the properties of the fluid, hence it is difficult to improve the performance of such instruments

On the 2nd floor, zjzcl168 (number 211752) covered the topic quite comprehensively. Two additional points regarding gas turbine flowmeters: 1. The operation of the start/stop controls for gas turbine flowmeters requires care; valves must be opened and closed slowly, and valves that can be opened or closed quickly, such as ball valves, should not be used, as this can easily damage the bearing system or the impeller； 2. The operating range requirements for gas turbine flowmeters are also high, typically ranging from 30% to 75% of the full scale; if the range is too low, the bearing speed becomes too low, resulting in unstable operation ； If the range is too high, the bearing speed will be too high, and prolonged operation will cause damage to the bearing system.