Compared with other types of flow meters, metal tube float flow meters have the following advantages and disadvantages:
advantage
High measurement accuracy: Within the normal working range, the measurement accuracy of metal tube float flow meters can usually reach around ± 1% to ± 2.5%. For some applications that require high flow measurement accuracy, such as fine production processes in pharmaceuticals and chemicals, it can meet their precise measurement needs.
Small pressure loss: Compared to some throttling flow meters, the pressure loss of metal tube float flow meters is relatively small. During the process of fluid passing through the flowmeter, there will be no significant pressure drop due to the presence of throttling elements, which can reduce the energy consumption of some systems with high pressure requirements, such as long-distance pipeline systems.
Wide range ratio: The range ratio of a general metal tube float flowmeter can reach around 10:1 to 20:1, and some high-precision products can even reach over 30:1. This means that under different flow conditions, only one flowmeter is needed to meet the measurement needs of a wide flow range, reducing equipment procurement and installation costs.
Wide range of applicable fluids: can measure various fluids, including liquids, gases, and vapors. For fluids of different properties, such as corrosive liquids, high-temperature and high-pressure gases, accurate measurements can be made by selecting appropriate materials and structural designs.
Intuitive reading: Metal tube float flow meters usually have intuitive scale indications, and operators can directly read the flow value from the scale dial of the flow meter without the need for additional signal conversion and complex display devices, making it convenient for on-site operators to monitor and adjust in real time.
shortcoming
Limited temperature and pressure resistance: The working temperature range of a general metal tube float flowmeter is usually around -20 ℃ to 120 ℃, and the working pressure generally does not exceed 10MPa. For some special working conditions of ultra-high temperature and ultra-high pressure, such as certain high-temperature and high-pressure chemical reaction processes or flow measurement in deep-sea oil and gas extraction, it may not meet the requirements.
Measurement of pipe diameter is limited: The measurement pipe diameter of metal tube float flowmeter is usually relatively small, generally between DN15 and DN200. For flow measurement of large pipe diameters, such as large water pipelines, long-distance oil and gas pipelines, multiple small-diameter flow meters need to be installed in parallel or other special installation methods, which increases the complexity and cost of the system.
High cleanliness requirements for the medium: Metal tube float flow meters require high cleanliness for the measured fluid. If the fluid contains solid particles or impurities, it may cause the float to jam or wear, affecting the normal operation and service life of the flow meter. Therefore, it is usually necessary to filter the fluid before use, which increases the maintenance workload of the system.
Not suitable for pulsating flow: When there are significant pulsations or fluctuations in fluid flow, the float will frequently bounce up and down in the measuring tube, resulting in unstable measurement results and increased errors. Therefore, metal tube float flow meters are not suitable for measuring high pulsating flow rates, such as measuring the outlet flow rate of certain reciprocating compressors.
Strict installation requirements: Metal tube float flow meters require high verticality and stability of the pipeline during installation. If the installation is not standardized, such as significant tilting or vibration of the pipeline, it can cause friction or collision between the float and the inner wall of the measuring tube, affecting measurement accuracy and the normal operation of the flow meter.
