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If a valve is installed at a distance upstream of the vortex flowmeter installation point, and that valve is opened and closed repeatedly, it has a significant impact on the flowmeter’s service life, and can very easily cause permanent damage to the flowmeter. Flow meters should be installed as far as possible not on very long overhead pipelines, as over time the downward sag of the flow meter can easily lead to leakage at the seal between the flow meter and the flange. If installation is unavoidable, pipe fastening devices must be installed 2D distances upstream and downstream of the flow meter. For vortex flowmeters, there are pipe-type models for diameters below DN300, and insert-type models for diameters above DN300. They can be used to measure the flow rate of various liquids and gases; they are capable of determining not only the volumetric flow rate but also the mass flow rate of the medium. Choosing the correct installation location and installing the flow meter properly are both very important steps. Errors in the installation process can, in mild cases, affect the measurement accuracy; in more severe cases, they can impact the flow meter’s service life or even damage the flow meter itself. Instrument coefficient of vortex flowmeter: It has been calibrated and tested before leaving the factory, and the instrument constant K for each flowmeter is indicated on the nameplate and the certificate of conformity. Its physical meaning is the number of pulses generated by the flowmeter per liter of fluid that passes through it under calibrated conditions (P=101.3 kPa, t=20°C), with the unit being 1/L. Due to changes in the temperature of the medium being measured, the geometric dimensions of the measuring pipeline and the vortex generator change as a result of thermal expansion and contraction; therefore, it is necessary to adjust the constants of the flow meter. The expression for the correction factor KT is: KT = 1 – 4.8×10^-5×(t–20), where t is the temperature of the medium being measured, in °C. Method for converting volumetric flow rate under operating conditions of vortex flow meters: (1). Calculate the volumetric flow rate under the actual pipeline operating conditions based on the flow rate range specified in the process. The flow rate specified in the process can be mass flow rate (kg/h), volumetric flow rate under operating conditions (m3/h), or volumetric flow rate at standard conditions (Nm3/h). The methods for converting mass flow rate or volumetric flow rate at standard conditions to the volumetric flow rate under operating conditions are as follows: a. Convert the maximum mass flow rate (upper limit of the range), Gmax (kg/h), into the volumetric flow rate Qmax (m3/h) using the following formula: Qmax = Gmax × ρ (m3/h), where ρ is the density of the medium under the operating conditions of the instrument (kg/m3). b. Convert the maximum flow rate at standard gas conditions (upper limit of the range), Q0max (Nm3/h), into the volumetric flow rate Qmax (m3/h) using the following formula: Qmax = Q0max × (P/ρ) (m3/h), where P is the gauge pressure of the gas under the operating conditions of the instrument (MPa) ； t —— Temperature of the gas under the operating conditions of the instrument (°C). (2). The maximum frequency fmax of the vortex street is calculated based on the maximum volumetric flow rate Qmax under operating conditions (m3/h): fmax = ───×Qmax×K×KT (Hz). Here, K is the instrument coefficient (1/L), and the value of K is indicated on the instrument’s nameplate ； KT──Temperature correction coefficient.