Pump Basics, Curves, & Field Calculations Flashcards
What is the Pupose of a Pump?
The basic purpose of a pump is _________________________. In order to do this, some amount of ________ (typically read as ___________) is generated to overcome height differences and frictional losses in the pump _______________________ at a given flow rate
The basic purpose of a pump is to move liquid from one point to another. In order to do this, some amount of head (typically read as pressure) is generated to overcome height differences and frictional losses in the pump casing and piping system at a given flow rate
How does a centrifugal pump work?
A specific diameter ______________ rotates at a given speed. Energy created by the pump at the _______________ is transferred to the liquid and corresponds to the ________________. Therefore, the greater the speed or larger the impeller diameter, the ________________ creating _________________________
A specific diameter impeller rotates at a given speed. Energy created by the pump at the impeller vane tips is transferred to the liquid and corresponds to the fluid velocity. Therefore, the greater the speed or larger the impeller diameter, the velocity increases creating higher energy (i.e. more head)
What is a centrifugal pump curve?
A diagram that shows a particular pump’s characteristics including the following:
___________ typically in GPM (USC) or m3/hr (SI); aka Q
Total Developed __________ in feet (USC) or meters (SI); aka H
_________________________________ (NPSHR) in feet absolute (USC) or meters absolute (SI)
________________ (BHP) required by the pump (book curves show BHP for SG=1) in hp (USC) or kW (SI)
Pump ____________ in %
A diagram that shows a particular pump’s characteristics including the following:
Flow (capacity) typically in GPM (USC) or m3/hr (SI); aka Q
Total Developed Head in feet (USC) or meters (SI); aka H
Net Positive Suction Head Required (NPSHR) in feet absolute (USC) or meters absolute (SI)
Brake Horsepower (BHP) required by the pump (book curves show BHP for SG=1) in hp (USC) or kW (SI)
Pump Efficiency in %
Total “Dynamic” or System Head (H) = Total _____________ minus Total ______________
Total “Dynamic” or System Head (H) = Total Discharge Head (hd) minus Total Suction Head (hs) (or plus Total Suction Lift (hs))
What is Discharge Head?
hd = ____________________ (from pump suction _______ to level or _____________________ in downstream vessel) plus any pressure in _______________ above atmospheric plus all piping and exit losses
Discharge Head:
hd = Static discharge head (from pump suction centerline to level or inlet elevation above level in downstream vessel) plus any pressure in discharge vessel above atmospheric plus all piping and exit losses
What is Suction Head?
suction _____________ level is above pump suction ______________
* hs = Static head (level above the pump suction centerline) plus any pressure above atmospheric (or less if vacuum pressure) less all piping and entrance losses
Suction Head: suction reservoir/drum level is above pump suction centerline
* hs = Static head (level above the pump suction centerline) plus any pressure above atmospheric (or less if vacuum pressure) less all piping and entrance losses
*
What is Suction Lift?
Suction Lift: suction reservoir level is below pump suction centerline
* hs = Static lift (level below to pump suction centerline) plus all piping and entrance losses
Suction Lift: suction reservoir level is below pump suction centerline
* hs = Static lift (level below to pump suction centerline) plus all piping and entrance losses
Velocity Head for a centrifugal pump is pressure expressed in the _____________ that a pump can produce and is based on ____________ velocity (in ft/sec) of the __________
Head (ft) = ______________
Velocity Head for a centrifugal pump is pressure expressed in the height of a liquid column that a pump can produce and is based on peripheral velocity (in ft/sec) of the impeller
Head (ft) = V2 / 2g
