A pump salesman gave a quotation for a centrifugal flow pump running at 850 rpm to deliver a flow rate of 3.0 m'/sec of water against a pressure head of 8 m, with an efficiency of 85%. The diameter of the pump inlet is 100 mm. Is this a realistic quotation? Figure 4 shows a specific speed chart and the specific speed for a rotary pump is given as: N, =- (gH)75 where wis the speed of the pump (radians per second), Q is the pump flow rate (m' per second), and H is the pump head (m). Specific Speed Chart shrouds rImpeller- shrouds -Impeller shrouds Impeller hub Hub- Vanes Hub Hub, Hub Vanes Axis of rotation Vanes Vanes Vanes Axial flow Mixed flow Radial flow 4. Specific speed, N, 0.2 - 0.3 - >0.4- 0.5- E9'0 0.7- F8'0 Foz -0'9 Fo'8