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Installation parameters for Yokogawa vortex flowmeters: Selection of sensor diameter: (suitable for DN300 and below), primarily to determine the lower limit of the flow rate. It should meet the following conditions: the minimum Reynolds number should not be lower than the threshold Reynolds number, and for the stress-based approach, the vortex intensity at the lower flow rate should be greater than the allowable value for the sensor’s vortex intensity (vortex intensity is proportional to lift). For liquids, it is also necessary to check whether the minimum operating pressure is higher than the saturated vapor pressure at the operating temperature, that is, to determine whether cavitation will occur. When determining the flow measurement range, it is also necessary to check whether it falls within the instrument’s optimal operating range, specifically between 1/2 and 2/3 of the upper flow limit. The selection and considerations can be approached from five aspects: the performance of the flow meter, the properties of the fluid, the installation conditions for Yokogawa vortex flow meters, environmental conditions, and economic factors. In terms of performance, the key aspects include accuracy, repeatability, linearity, range, flow range, signal output characteristics, response time, pressure loss, etc ； Properties include: temperature, pressure, density, viscosity, chemical corrosion, abrasiveness, structure, multiphase state, phase transition, electrical conductivity, sound speed, thermal conductivity, specific heat capacity, isentropic index ； Regarding installation conditions: pipeline layout direction, flow direction, length of straight sections upstream and downstream of the sensing element, pipe diameter, maintenance space, power supply, grounding, auxiliary equipment (filters, degasers), installation, etc ； Environmental conditions: ambient temperature, humidity, electromagnetic interference, safety, explosion protection, pipeline vibration, etc. The selection of the instrument diameter and specifications for Yokogawa vortex flowmeters is very important; it is similar to the design calculations for the throttling elements in differential pressure flowmeters, and certain principles must be followed for making such selections. Selection of gauge diameter. First, several working parameters must be clarified. Such as: fluid name, components ； Maximum, normal, and minimum flow rates in operating condition ； Maximum, normal, minimum operating pressure and operating temperature ； Viscosity of the working medium. The diameter of the instrument selected according to the above principles need not necessarily match the pipe diameter; if they differ, special-shaped pipes should be used along with a sufficient length of straight pipe section. Compared to traditional vortex flowmeters, the Yokogawa vortex flowmeter requires shorter straight pipe sections before and after it. If there are insufficient straight sections upstream and downstream, the fluid will not develop adequately, resulting in vortices and distorted velocity distribution profiles. Distortions in the flow velocity profile are usually caused by local obstructions in the pipeline, such as valves or bends, whereas vortices are generally induced by two or more spatially arranged bends. Insufficient straight sections upstream and downstream can be adjusted by installing flow regulators. The simplest and most effective approach is to use a flow meter that has lower requirements for the straight sections upstream and downstream. The range ratio refers to the ratio of the maximum flow rate to the minimum flow rate that a flow meter can measure within the range where it can maintain a given level of accuracy and repeatability. But we must be careful when it comes to the range ratio, as it is based on the actual flow rate. The maximum allowable flow rate in steam systems is generally a certain value; higher flow rates can cause erosion and noise in the system. Moreover, the minimum flow rates allowed by different flow meters vary; generally, vortex flow meters can measure a minimum steam flow rate of 2.8 m/s. In cases where the range ratio is insufficient, flow meters with a larger range ratio are required. Based on the field usage of Yokogawa vortex flowmeters, temperature measurement errors are related not only to the inherent errors of the temperature sensing elements but also to improper installation. For example, insufficient insertion depth of the temperature-sensing platinum resistance, failure to fill the protective sleeve surrounding it with heat-conducting oil, incorrect lateral installation of the platinum resistance, and the absence of an insulating layer on the pipe where it is installed – all of these can result in lower temperature readings. For steam that requires pressure reduction, the flow meter should be installed before the pressure reducing valve; at this point the steam is not yet under reduced pressure, and the saturated steam compensation method can be used to ensure measurement accuracy. If the flow meter can only be installed behind the pressure reducing valve, steam may cause issues; therefore, temperature and pressure compensation must be carried out simultaneously to ensure accuracy