I thought at upper taping there should not be any entry loss so P1=P3 whatever the flow of FLO. This is because if FLO flows from a pipe falls into a COLUMN (or whatever), the diameter of the FLO stream after the exit does not change, its velocity does not change, there is no turbulence outside...
There is Differential pressure (DP) type level tranmitter to measure level inside the column. There is flushing oil (FLO) connection in both the lower and upper tapings of DP type level. This is because the fluid inside the column is tend to choke the tapings for level measurement, so to avoid...
