Centrifugal Pumps Flashcards
Describe the purpose of the impeller in a centrifugal pump
Pushes water from the eye outwards increasing pressure using centrifugal force
List the 3 types of impellers used in centrifugal pumps
Open, semi-open, closed
How does liquid enter the impeller?
The eye
Describe the advantage of double suction propellers
requires less NPSH compared to single suction impellers
Describe the function of pump casing
Directs fluid from suction, to the impeller and to discharge
List three different types of casing designs used in centrifugal pumps
Single volute, double volute, diffuser
Describe the purpose of wear rings
They are components used to minimise the leakage of fluid between the impeller and pump casing
(Sacrificial metal)
Describe the function of bearings
They maintain correct alignment between the rotor and the pumps stationary components under both radial and axial loads
4 was to prevent bearing failure
Oil mist is functioning correctly.
Lube oil in wet sump bearing housing is kept clean and at proper level.
Early detections and correction of vibration and high bearing temperatures
Pump operates in its reliable range
Describe the function and purpose of the seal system
Prevents the pumped fluid from leaking between the shaft and casing into the atmosphere
Describe the purpose of the seal flush system
Provides seal cooling, lubrication and cleaning
Describe the function and purpose of the lubrication system
Is required to keep the rotating and non-rotating parts from overheating and seizing
Describe function of each of the lubrication methods: oil mist, wet sump, grease, force feed, product
Oil mist: oil that atomizes in air that covers everything
Wet sump: maintains a constant lubricant level at which the bearing is in
Grease: good for dirty/wet applications, simple housing
Forced feed: used for cooling and lubrication, a self contained system
Product: uses process product as lubrication
Describe the function of a driver
Provides energy to the pump so that it can do work
Describe function of coupling
Drivers are connected to the pump through coupling
