i'm having a problem that's driving me crazy, we have a PV that controls the pressure in a a vessel through allowing gaseous nitrogen into the vessel to increase pressure whenever needed. we can view the output of the valve on the DCS, however we can't track the flow of nitrogen into the vessel.
i need to calculate the flow of nitrogen through the valve, what i'm told is that i need to make a relation between the output and Cv, then a relation between Cv and flow. i don't have enough data to make the relations, i have 3 points for the relation between Output and Cv, ( @ 0, 100, middle value).
and just 2 points for the relation between Cv and Flow (@ 0 and middle value).
what can i do?
P.S the valve characteristic is equal percentage.
i need to calculate the flow of nitrogen through the valve, what i'm told is that i need to make a relation between the output and Cv, then a relation between Cv and flow. i don't have enough data to make the relations, i have 3 points for the relation between Output and Cv, ( @ 0, 100, middle value).
and just 2 points for the relation between Cv and Flow (@ 0 and middle value).
what can i do?
P.S the valve characteristic is equal percentage.