There are many kinds of flowmeters in the current flowmeter market. Metal tube rotameter and glass rotameter belong to the same kind of rotameter. Glass rotameter is cheap, practical and convenient. Compared with gold rotameter and glass rotameter, the price is higher. But now the use rate of metal tube rotameter is increasing rapidly, replacing glass tube flowmeter slowly. Because the metal tube rotameter has stable performance, complete functions and easy operation, it can also be output with 4-20mA signal. Metal tube rotameter is suitable for measuring liquid and gas flowmeters in closed pipes.

The good performance of the flowmeter is one aspect. Reasonable installation and correct use can make the flowmeter prolong its service life and ensure the accuracy of the flowmeter.

In order to ensure the normal operation of metal tube rotameter and meet the required measurement accuracy, the following points should be paid attention to in general:

1. The outlet shall have 250mm straight pipe section, and the inlet of metal tube rotameter shall have a straight pipe section of more than 5 times the diameter of the pipe. To ensure the accuracy of instrument measurement;

2. Flow through flowmeter from bottom to top. Metal tube rotameter must be installed vertically, and the verticality is better than 2 degrees. Horizontal angle is better than 2 degree when installed horizontally, so as not to affect production when dealing with faults or blowing washing. Metal tube rotor flowmeter installed in process pipeline should be bypassed.

3. If there are solid impurities and ferromagnetic materials in the medium, it should be considered to install filters between the valve and the straight pipe section.

4. When thermal insulation measures are needed, crystallization occurs easily if the temperature of the measured medium is higher than 220 C or the temperature of the fluid is too low. The jacket type should be selected for cooling or heat preservation.

5. Instruments for measuring gas should ensure that pipeline pressure is not less than 5 times the pressure loss of flowmeters in order to make the float work steadily. If the gas is directly discharged into the atmosphere at the outlet of the instrument, the pressure drop at the float will be generated and the data will be distorted. If this is the case, a valve should be installed at the outlet of the instrument.

6. Metal tube rotameter generally does not need maintenance after normal operation of the device. Faults often occur when the device is just started, because the pipeline is not clean, and the float is stuck by solid particles. At this time, the pointer of the indicator stops at a fixed position. At this time, we should first close the valves on both sides of the flowmeter, then remove the upper flange, remove the float for cleaning, and then re-install it. Attention should be paid to tightening the flange nut balanced tightening, and gaskets.