Installation of vortex flowmeter
Thread Content
There are two vortex flowmeter main meters installed in front of the gas storage tank, with sub-meters placed behind the tank. Neither of these flowmeters features temperature and pressure compensation; the density set value at the site is 8. Currently, the flow rate after the gas storage tank is higher than that before it. I seek guidance from experts to understand why this is the case.
Are the diameters of the pipes at the front and back of the air storage tank the same? In other words, are the diameters of the two flowmeters the same?
Regardless of the degree of difference or the magnitude involved, without temperature and pressure compensation, I think it’s quite good to be within ±90%. To obtain accurate measurements, temperature and pressure compensation is required.....
What is the medium of the fluid? What are the pressure and temperature of the fluids before and after the air storage tank?
It is meaningless to compare gases without pressure stabilization compensation, unless you can ensure that the temperature and pressure of both are always identical.
It seems that the pressure at the main gauge might be unstable, as it is affected by the operating conditions upstream; whereas the sub-gauges, thanks to the air storage tank, have relatively stable pressure and temperature
Based on what the original poster has said, it might be useful to consider a scenario in which certain conditions are met: 1. Assume that the temperature and pressure at the locations of the two flow meters remain stable； 2. Assume that all the measured flow rates are within the appropriate measurement range of the flow meter. Under the above conditions, the mass flow rate through the two flow meters is actually the same. Since the air storage tank causes pressure loss, the pressure at the flow meter located after the tank is always lower than the pressure at the flow meter located before it. Based on the relationship between the flow rate under operating conditions and the flow rate under standard conditions, the flow rate through the flow meter after the air storage tank is greater than the flow rate through the flow meter before the tank ； The two flow meters did not undergo temperature and pressure compensation; instead, the same density setting was used for correction. As a result, the flow rate value calculated for the flow meter located after the gas storage tank is higher.
A gas flow meter ignores temperature and pressure and fixes the density directly; in such a case, any talk about accuracy is nothing but nonsense!
1 Are the straight pipe sections before and after both flow meters meeting the requirements? 2 Are the temperature and pressure of the medium flowing through the two flow meters the same? 3 Are the parameter settings exactly the same? Otherwise, it is not surprising to see deviations.