2. A light lube oil (sp.gr. =0.87, viscosity =3cP ) is pumped by a rotary gear pump to a storage tank at a rate of 1000 gal/hr. The piping system consists of 450 feet straight pipe of 1 inch in diameter sch. 40 (commercial steel pipe), five standard elbows, one standard tee (through side outlet) and one globe valve. Changes in velocity and pressure are assumed to be neglect. The centerline of pump is above the oil level 4 feet for suction side while the discharge side is above the pump 6 feet. (a) Calculate the total head of the pump. (b) Estimate the required power for electric motor if the pump efficiency is 75% and motor efficiency is 85%. (c) If electricity cost is 5 Baht/unit, find the annual cost of electrical pumping. (Pump operates 20hr/ day and 350 days/year). Figure A The schematic painping diagram for qutation 2