The maximum demand upon a steam accumulator $($i$.$e$.,$ one of the sectional areas in Fig. $2-14)$ is $65,000$ lb steam. Maximum charging pressure is $350$ psia, dry and saturated steam. The delivery pressure, beyond valve B$,$ is $30$ psia. Assuming that the accumulator is fully charged just previous to the period of maximum demand, calculate the lb water the accumulator must contain if this maximum demand is to be only $75\%$ of the accumulator's steam capacity.