Abstract: This paper presents the detail design of impeller and volute casing for double-suction centrifugal pump. The designed pump can develop a head of 150 ft (46 m) and deliver 335 ft3/min or 2500 gal/min (9.48 m3/min) of clean and cold water at the speed of 1760 rpm. The designed impeller has 7.32 in (19 cm) inlet diameter, 13.5 in (34 cm) outlet diameter, 13˚ inlet vane angle and 20˚ outlet vane angle. The number of vanes is 7. The inlet width and outlet width are 1.75 in (4 cm) and 1.98 in (5 cm) respectively. The discharge diameter is 6 in (15 cm) to operate the designed head and capacity.