Aqueous reagent is drawn from a headtank 10m above through a long pipeline. 30L/min passes into an open reaction vessel with no valve in the line at all. To reduce nonlinearity in the planned flow control loop, an "equal percentage" valve with characteristic f(x)=Kx1 has been selected to be implemented. If K=60, choose a suitable valve CV (use your own units) to obtain 50% of the maximum flow (x=1) when the valve is half open (x=0.5)