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1. Accuracy level: Generally speaking, turbine flowmeters are chosen primarily due to their high accuracy. However, the higher the accuracy of the flow meter, the more sensitive it is to changes in field operating conditions. Therefore, careful consideration must be given to the choice of instrument accuracy, taking economic factors into account. For trade settlement instruments in large-diameter gas pipelines, it is cost-effective to invest more in such instruments. For applications with low throughput, a medium precision level is sufficient. 2. Flow range: The selection of the flow range for a turbine flow meter has a significant impact on its accuracy and service life. Moreover, each size of flow meter has a specific measurement range, and the choice of flow meter size is also determined by the flow range. The principle for selecting the flow range is that the minimum flow rate during use should not be lower than the minimum flow rate that the instrument can measure, and the maximum flow rate during use should not be higher than the maximum flow rate that the instrument can measure. For applications with intermittent operation where the actual daily operating time of the instrument is no more than 8 hours, 1.3 times the maximum flow rate during actual use is taken as the upper limit for the flow range; for applications with continuous operation where the actual daily operating time of the instrument is 8 hours or more, 1.4 times the maximum flow rate during actual use is taken as the upper limit for the flow range. The lower flow limit for the instrument is appropriately set at 0.8 times the minimum flow rate in actual use. 3. Gas density: For gas turbine flowmeters, the influence of fluid properties is primarily the gas density. It has a significant impact on the meter coefficient, mainly in the low-flow range. If the gas density changes frequently, corrective actions must be taken regarding the flow coefficient of the flow meter. 4. Pressure loss: Choose turbine flowmeters with low pressure loss as much as possible. Because the pressure loss of the fluid as it passes through the turbine flow meter is the smaller, the less energy is consumed by the fluid as it moves from the inlet pipe to the outlet pipe; in other words, the total power required is reduced, which allows for **energy savings, lower transportation costs, and improved efficiency**. 5. Structural type: (1) For the internal structure, a back-pushing turbine flow meter is recommended. Because the reverse thrust structure allows the impeller to remain in a floating state within a certain flow range, with no contact points in the axial direction and thus no end-face friction or wear, which helps to extend the service life of the bearings. (2) The selection is based on the piping connection method; flow meters can be installed horizontally or vertically. For horizontal installation, the piping connection methods include flange connection, threaded connection, and clamp connection. Flange connections are used for medium-diameter pipes; threaded connections are used for small-diameter and high-pressure pipes. Clamping connections are only suitable for low-pressure pipes of small to medium diameter; threaded connections are the only option for vertical installations. (3) Select the model based on environmental conditions, taking into account the effects of temperature and humidity. For natural gas metering, an intrinsically safe explosion-proof turbine flowmeter should be selected. 6. Bearings: The bearings in turbine flowmeters are generally made of three materials: tungsten carbide, polytetrafluoroethylene, and carbon graphite. The bearings of natural gas metering instruments should be made of tungsten carbide. These are the main factors to consider when making a selection. Given the wide variety of types and specifications available for turbine flowmeters, and especially the differences in product quality among different manufacturers, it is advisable to gather as much information as possible regarding the technical standards of the manufacturers and their products before making a decision. Repeated research and comparison should be carried out before choosing a particular model.