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Flow measurement is an important basis for corporate economic accounting. Accurate and reliable flow measurement is a prerequisite for ensuring the normal operation of enterprises, and it is one of the key means to achieve optimal economic benefits. The following details the precautions that need to be taken for the installation and maintenance of metal tube float flow meters. I. Precautions for installing metal tube float flow meters: 1. Before installing a metal tube float flow meter in the process pipeline, the pipeline should be purged to remove any weld slag from it; this prevents impurities in the pipeline from blocking the instrument and affecting its proper operation. 2. To ensure measurement accuracy, it is recommended to install a 5DN inlet straight pipe section upstream of the flow meter, and a 250 mm outlet straight pipe section downstream. 3. Metal tube float flowmeters are available in vertical and horizontal installation styles. In the vertical installation style, the verticality should be maintained at a level better than 1%, while in the horizontal installation style, the levelness should also be kept at a level better than 1%. 4. If the medium contains solid impurities, a filter should be installed between the valve and the straight pipe section; if the medium contains ferromagnetic substances, a magnetic filter should be installed upstream of the metal tube float flow meter. 5. Since a magnetic remote transmission system is installed in the metal tube float flowmeter, it is necessary to ensure that magnetic fields generated by other devices in the vicinity do not affect the measurement results. 6. If the medium being measured is a flow with significant pulsations or a two-phase flow, a buffer should be installed upstream of the flow meter to eliminate or reduce these pulsations and ensure that the flow is single-phase and stable. It is also recommended to use a flow meter with damping capabilities. 7. Flow meters used for measuring gas flow are calibrated under specific pressures. If the gas is released directly into the atmosphere at the outlet of the flow meter, a significant pressure loss will occur at the float, resulting in distorted data. In such conditions, a valve should be installed at the outlet of the flow meter to allow for the setting of the desired flow rate. When a calibrated pressure is maintained above the float, the gas will expand at the valve. 8. To facilitate cleaning and maintenance and ensure the normal operation of production, it is recommended to install a bypass pipeline. 9. The axis of the installation pipeline must be coaxial with that of the flow meter, and the pipeline should be properly supported to avoid vibration and reduce the stress on the flow meter; the control valve of the measurement system should be installed downstream of the flow meter. 10. When installing a metal tube float flow meter with a PTFE lining, tighten the flange bolts symmetrically and not too tightly to prevent deformation of the PTFE. II. Precautions for the maintenance of metal tube float flow meters: 1. Metal tube float flow meters are precision devices; therefore, during transportation, installation, storage, and use, they must be handled with care. Rough handling, forced installation, and leaving them in random locations should be avoided. It is essential to ensure that the relative positions of the indicator and the sensor do not change; once this relative position changes, it will directly affect the measurement accuracy of the instrument. 2. Metal tube float flow meters generally do not require maintenance. However, over time, ferromagnetic substances inevitably adhere to the float within the pipeline. If there are too many impurities, they can jam the float or affect the measurement accuracy; therefore, it is necessary to clean the sensor of the flow meter. If a magnetic filter is installed at the inlet of the flow meter, it also needs to be cleaned regularly. The flow meter or filter must be removed from the pipeline during cleaning. 3. Before using electric remote transmission flow meters equipped with alarm limit switches, open the instrument cover and connect the wires correctly according to the instructions. For the screws at the alarm-type loosening limit switch, the user sets the limit alarm position as needed, tightens the screws, and then uses it once it has been restored to its normal state. 4. When used for gas measurement, it is necessary to ensure that the pipeline pressure is at least 5 times the pressure loss of the instrument, in order to guarantee stable operation of the float. Instruments for measuring gases are generally equipped with gas dampers to minimize float oscillation. To further ensure the stability of the float, a throttle valve or an appropriate orifice plate can be installed at the outlet of the flow meter. 5. When using a metal tube float flow meter, the valve should be opened and closed slowly to prevent damage to the instrument. If the flow meter is turned on, and there is no pressure in the pipeline or the system has not yet reached the operating pressure required for the meter to function properly, it is necessary to open the control valve slowly until the system is in proper condition; otherwise, this can cause the pointer to fluctuate or the float to collide suddenly, leading to damage. 6. When in use, if the density of the fluid being measured differs from that of water, or if the parameters and operating conditions of the gas being measured differ from those specified by the manufacturer, it is necessary to convert the readings indicated by the flow meter; the method for such conversion is outlined in the corrections section.