In the pipe system shown below the pipe has a diameter of $49$ cm$,$ and it is $230$ m long. The equivalent roughness height of the pipe, e$,$ is $0\mathrm{.}18$ mm$.$ The kinematic viscosity is n $=1\mathrm{.}13\backslash$times $10-6$ m$2/$s$.$ The minor head loss coefficients are: Ke $=0\mathrm{.}5$ for entrance losses, and Kd $=1\mathrm{.}0$ for exit losses. The water surface elevations are h$1=69\mathrm{.}0$ m$,$ and h$2=30$ m$.$ The discharge is Q $=0\mathrm{.}25$ m$3/$s$.$

Determine the valve head loss coefficient, Kv$.$