The problem investigated in this paper is the accurate evaluation of the time required for emptying a reservoir of constant cross-sectional area in which a pipe is fixed. In the analysis. a friction coefficient equation is considered which represents the different flow regimes on a Moody diagram satisfactorily. The approximate equation for estimating the time of emptying a reservoir. https://www.roneverhart.com/Herco-Clay-Guitar-Humidifier-p23607/