A tank farm consists of a supply tank A located at an elevation of 80 ft above mean sea level (MSL) and a delivery tank B at 90 ft above MSL. Two identical pumps are used to transfer liquid from tank A to tank B using interconnect pipe and valves. The pumps are located at an elevation of 50 ft above MSL.
The suction piping from tank A is composed of 120 ft, 14 in. diameter, 0.250 in. wall thickness pipe, six 14 in. 90° elbows, and two 14 in. gate valves. On the discharge side of the pumps, the piping consists of 6000 ft of 12.75 in. diameter, 0.250 in. wall thickness pipe, four 12 in. gate valves, and eight 12 in. 90° elbows. There is a 10 in. check valve on the discharge of each pump. Liquid transferred has a specific gravity of 0.82 and viscosity of 2.5 cSt.
(a) Calculate the total station head for the pumps.
(b) If liquid is transferred at the rate of 2500 gal/min, calculate the friction losses in the suction and discharge piping system.
(c) If one pump is operated while the other is on standby, determine the pump (Q, H) requirement for the above product movement.
(d) Develop a system head curve for the piping system.
(e) What size electric motor (95% efficiency) will be required to pump at the above rate, assuming the pump has an efficiency of 80%?
