Instrument structure and installation method of natural gas flow meters

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　　As a high-quality energy source and chemical raw material, the measurement of natural gas is receiving increasing attention. At the same time, natural gas flow meters feature high measurement accuracy, a wide range, low power consumption, easy installation, simple operation, and minimal pressure loss. They can measure volumetric flow rate under operating conditions or standard volumetric flow rate (with integrated intelligent temperature and pressure compensation). Depending on user requirements, they can be equipped with pulse or 4–20 mA DC current output functions. The following describes in detail the structure and installation methods of natural gas flow meters: 1. The installation of natural gas flow meters can be done using flange connections, threaded connections, or clamp-type connections; 2. When installing a natural gas flow meter, the direction of fluid flow should be consistent with the arrow indicating the flow direction on the sensor’s housing. The upstream straight pipe section should be at least 10dn in length, while the downstream straight pipe section should be at least 5dn in length (dn refers to the inner diameter of the pipe). 　　3. The sensor of the natural gas flow meter should be kept away from external magnetic fields; if this cannot be avoided, necessary measures should be taken. 4. To ensure that the normal flow of liquid is not affected during maintenance, bypass pipes should be installed outside the straight sections at both ends of the sensor. 5. When the natural gas flow meter is installed outdoors, proper waterproofing measures should be taken for the amplifier connectors. 6. The wiring between the natural gas flow meter and the display instrument should be arranged according to the power supply requirements of the amplifier; for details, refer to the relevant “User Manual”. 　　7. The natural gas flowmeter sensor can be installed horizontally or vertically; when installed vertically, the fluid flow direction must be upward. The pipeline should be filled with liquid, without any bubbles. During installation, the flow direction of the liquid should be consistent with the arrow indicating the flow direction on the sensor housing. There should be a straight pipe section of at least 10 times the nominal diameter length upstream of the sensor, and at least 5 times the nominal diameter length downstream. Its inner wall must be smooth and clean, free from defects such as dents, deposits, and peeling. 　　8. If the fluid is unstable and exhibits pulsating flow, a buffer can be installed to ensure accurate measurement by the gas flow meter, thereby eliminating the pulsations. When using a natural gas flow meter, the control valve on the pipeline upstream of the meter should be slowly opened first, and then the flow rate should be adjusted using the control valve, in order to prevent sudden opening from causing the float to rise rapidly and damage the cone-shaped tube. 　　Flow metering is one of the components of metrological science and technology, and it is closely related to the national economy, national defense construction, and scientific research. Doing this work well plays an important role in ensuring product quality, improving production efficiency, and promoting the development of science and technology. Especially in today’s era of energy crises and increasing automation in industrial production, the significance and role of flow meters in the national economy have become even more evident.