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Pump Selection. Centrifugal - low P (<3.5 MPa), low viscosity, high flow rates Rotary positive displacement - medium P (<20 MPa), medium viscosity, medium flow rates Reciprocating - high P (<150 MPa), high viscosity, low flow rates Special issues - corrosion and abrasion
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Pump Selection • Centrifugal - low P (<3.5 MPa), low viscosity, high flow rates • Rotary positive displacement - medium P (<20 MPa), medium viscosity, medium flow rates • Reciprocating - high P (<150 MPa), high viscosity, low flow rates • Special issues - corrosion and abrasion • See Figure 12-3 course pack
What determines pump size? • Operating pressure • Elevation change • Acceleration of fluid • Frictional losses
Centrifugal Pump Curves • Flowrate • Total head • Power • Efficiency • NPSH • Impeller size
Schematic Pump Curve • TDH? units? • GPM? • %? • HP? • NPSH? units? • What is in inches?
Pump NPSH Net Positive Suction Head (NPSH) = Head required at suction of pump in excess of the bubble pressure of the fluid at the pump temperature Why does this matter?
Pump costing • Based on power • Affected by • Materials • Operating pressure • Type of pump • Adjust for…
Pumps FBM is a function of material and pressure factors.
Suction pressure? Discharge pressure?