# Problem 3: Determine the Total Maximum Differential Pump Head (in terms of Feet of Flowing Fluid or FFF – we have just been calling this head) for…

Problem 3: Determine the Total Maximum Differential Pump Head (in terms of Feet of Flowing

Fluid or FFF – we have just been calling this head) for the system shown below. The pump isto transfer a design flow of 1000 gpm of a weak acid. The weak acid has a specific gravity0.9944 and viscosity equal to 1 cP at flowing conditions of 60°F. The discharge line rises 50 ftvertically above the pump centerline and then runs 400 ft horizontally to a receiver tank opento the atmosphere, where it drops to the liquid surface of the tank. Atmospheric pressure is14.7 psia. There is one 90° flanged elbow in this discharge line plus a sudden contraction. Thereis also a sudden contraction, a 90° elbow, and a gate valve on the suction line. All piping is 6inch, Schedule 40, steel pipe. The minimum level in the vacuum receiver is 4 feet above thepump centerline. The pressure on top of the liquid in the vacuum receiver is maintained at 20inches of mercury vacuum (meaning it is 9.82 psi below atmospheric pressure). The totalsuction piping pressure loss is 1.97 FFF (formally you would determine this number from all ofthe components present – a square edge inlet (sudden contraction), 4 feet of 6-inch Schedule40 pipe, one gate valve, and the 90° elbow – to simplify, I have given you the friction loss onthe suction side that accounts for pipe friction and the minor losses). The total dischargepiping pressure loss is 30.27 FFF (this accounts for pipe friction and minor losses). [101.1 ft]Repeat Problem 3 – the only difference being that the discharge line has a verticalleg inside the discharge tank that extends downward a distance of 10 feet from where itenters the tank. There is an additional 12 feet of piping in this arrangement and another 90°flanged elbow. The pipe is all 6-inch Schedule 40. The system is illustrated below. [93.2 ft]Repeat Problem 4 – the only difference being that the vertical leg of the dischargeline inside of the tank extends down an additional 5 feet and discharges 3 feet below thesurface of the liquid. The system is illustrated below. [89.5 ft]