What should be considered when measuring steam flow?
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I would like to ask everyone, what should be taken into consideration when measuring steam flow? Here, we use a split-type V-cone flow meter to measure the steam flow rate (the pressure sensing device is a V-cone flow meter installed in a split configuration; pressure guide tubes are used, and the transmitter is a differential pressure transmitter from Yokogawa EJA)
Attention should be paid to the temperature; steam must not accumulate here
Pay attention to the straight sections before and after installation, the addition of a condensate tank, the installation of the three-valve assembly, and the orientation of the pressure sampling points, etc； Pay attention to the steps involved in submitting the form to prevent damage to the instrument ； For routine maintenance, pay attention to checking connectors and valves to prevent leaks and other issues.
The straight sections at both the beginning and end meet the design requirements, but this table shows the lowest point of all steam pipes
Pay attention to the pressure tapping location on the pipeline; ensure that the three-valve assembly is closed in both positive and negative directions before putting it into use, and wait until the steam has condensed before operating it
If it is superheated steam, temperature and pressure compensation must be added. For saturated vapor, only temperature compensation is needed
The most important thing is to avoid getting scalded by the steam. To measure steam, differential pressure flow meters (consisting of a differential pressure element and a differential pressure transmitter) or vortex flow meters are generally used. If the differential pressure method is used, reliable temperature and pressure compensation must be carried out ； For diluted steam and superheated steam, it is even more important to accurately calculate the process parameters and medium conditions. Regarding the use of vortex flowmeters, some modern intelligent or digital vortex flowmeters come equipped with a compensation mechanism that allows for accurate measurement of saturated steam. However, for superheated steam or diluted steam, compensation using two parameters is necessary.
The installation location of the package, the balance of the sealing fluid – do not open the balance valve casually.
Be aware that temperature and pressure compensation is required; when I designed it, I used the Yokogawa EJX910 transmitter, and attention also needs to be paid to the orientation of the pressure guiding tubes in the measurement pipeline
The measurement of steam generally involves installing a condenser at the sampling point, with the transmitter positioned below the pressure sampling point. Its main function is to condense steam and prevent the transmitter from being damaged by heat!
For horizontal pipes, pay attention to the pressure tapping direction, the location of the condenser tank, the diameter of the pressure guiding pipes, and the insulation of the pipes.