The installation of the mass flow meter
Author:vacorda Source:vacorda.com Date: 2018-08-21 14:51:33
The mass flow meter is the instruments with most accurate and minimum installation requirement in the measurement industrial production. Because it can directly detect the mass, density and temperature of the medium flowing through the measuring tube inside the meter, it’s not very strict with the flow state of the medium. Therefore, there is no requirement for straight pipe sections for the pipelines before and after the flow meter during the installation process, as can be installed as the regulating valve, which greatly facilitates the construction and installation on site.
The mass flow meter has various shapes, but its internal structure is almost the same. Basically, there are two U-shaped measuring tubes. Three coils are installed on the bottom and left and right sides between the two measuring tubes, and the coil at the bottom is the exciting coil. On the left and right side, one coil detect mass, and another coil detect density, and the thermal resistance is buried inside the measuring tube to inspect the temperature.
Details of the installation process
Since the mass flow meter can detect the density of the medium in real time without artificially setting a constant density of the medium, the detection value of the mass flow meter is accurate and reliable, and the construction and installation are simple and convenient.
Although the mass flowmeter has no requirements for the front and rear pipelines of the flowmeter during construction and installation, there are some details to be noted during the installation process:
It is necessary to ensure that the front and rear process flanges of the flowmeter are welded concentrically, which can eliminate the additional torque caused by the difference of the flange during the installation process and reduce the use error of the mass flowmeter;
Also pay attention to some supporting construction processes, especially the eccentric torque during the heating line laying process and the impact of additional stress on the operation of the flowmeter;
Although the mass flowmeter measuring tube is inside the outer casing, the external stress can still cause unpredictable additional errors to the detection, such as the fixed wire of the heating wire in the figure, recovering the influence of temperature during operation and causing deformation to cause a randomly varying stress. Superposition
The laying of the heating line should also be separated from the mass flow meter to prevent the asymmetric stress generated by the thermal expansion of the heating line and the excessive conduction heat from affecting the temperature detection of the mass flow medium.