Relationship between the installation positions of the pressure relief valve and the flow meter
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I would like to ask which expert knows what are the differences between installing the pressure relief valve in front of, behind, or beside the flow meter during gas measurement?
The selection of the flow meter varies depending on whether it is installed before or after the pressure reducing valve.
It depends on the specifications of your flow meter and pressure regulator. If you haven’t yet chosen a model, since flow meters generally require fewer requirements regarding the straight pipe section downstream of them, it is more reasonable to determine the appropriate model after installing the pressure regulator behind the flow meter
1. After pressure reduction, the tube is generally enlarged (but the pressure is lowered), and the diameter of the flow meter increases; price factors are taken into consideration here. 2. Flow meters require straight pipe sections (especially upstream of the meter), and the choice should be based on the actual layout of the pipes. 3. The density of a gas is related to its pressure; changes in pressure result in changes in density, and this leads to errors in the flow meter. Is the pressure upstream of the pressure relief valve stable? My choice: If the price of option 1 is similar, place the flow meter downstream of the pressure reducing valve, ensuring that the requirements for a straight pipe section are met. But in the case of a flow control valve, the flow meter must be located upstream of the valve, because the pressure (density) downstream changes as the valve opens, which causes errors in the flow meter’s readings. @jiaguoyun