Precautions for maintaining metal tube float flowmeters

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1. It is essential to keep the instruments clean; in particular, the surfaces of the orifice plates and cones within the instrument, as well as the floats, must remain clean. Therefore, the instruments should be removed for cleaning after they have been in use. 2. The two covers of the controller must be tightly sealed to prevent dust from entering and interfering with normal operation. 3. If the instrument does not operate stably and the pointer fluctuates, in addition to the electronic pulses generated by the flow rate itself, it is necessary to consider the possibility of two-phase flow as the cause (that is, the simultaneous presence of a liquid phase and a gas phase). By taking measures to eliminate such two-phase flow, the instrument can operate steadily. Several points should be noted when installing a metal tube float flow meter: 1. To prevent damage during transportation, the gauge is equipped with a rubber band that holds the pointer in place; before making connections, the left cover of the gauge should be removed so that the pointer can be adjusted gently without causing any change in its position. 2. Open the right cover of the actuator; after the cable is inserted through the cable introduction device and the wiring is completed according to the transmitter’s wiring diagram, tighten the compression nuts to secure the cable. Then, tighten the fastening screws on both the left and right covers to make the actuator waterproof and dustproof. 3. Remove the flange-shaped float guide ring from the survey tube, take out the damping element that prevents the float from vibrating during transportation, and then reinstall it as before. 4. The flow meter should be installed vertically or in a pipe free from oscillations, without any risk of water damage; a bypass pipe is advisable for easy maintenance. For vertically installed flowmeters, the flow direction of the medium being measured must be from bottom to top. The valve must be installed downstream of the survey location. A certain length of straight pipe section should be ensured at the inlet and outlet of the flow meter. If the medium being measured contains solid particles, an appropriate strainer should be installed; if it contains magnetic particles, a magnetic strainer should be used. 5. When installing Ex-proof flow meters, it is essential to comply with the Electrical Safety Regulations for Explosive Hazardous Areas in the People’s Republic of China.