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70 Cards in this Set
- Front
- Back
What is the common name for a variable displacement pump |
Centrifugal |
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List four reasons for using a centrifugal pump |
Easy to produce Small and lightweight Many convenient forms of drive Good at moving liquid |
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What brings water into the eye of a centrifugal pump |
Impellers |
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Impellers take the fluid and force it through gradually widening passages called |
Vanes |
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Rule: as velocity decreases |
Pressure increases |
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Multiple impeller design can add more ___________ to the water leaving the pump than a single impeller design |
Pressure |
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Adding more impeller stages does not increase the flow of the fluid leaving the pump, only its |
Pressure |
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For maximum efficiency, the pump case must be |
Full of water |
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The act of the impeller spinning creates what type of pressure |
Negative |
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The lift capability of the pump depends on several factors |
Atmospheric pressure Friction loss in the supply pipe Condition of the pump |
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The maximum theoretical lift of a centrifugal pump at sea level is |
34 feet |
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Theoretical lift of 34ft is equal to |
14.7psi divided by the weight of water per foot of height |
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The maximum practical lift at sea level is |
25 feet |
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The practical lift of a pump must be reduced 1 foot for every _______ ft of elevation |
1000 |
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Pump designers consider centrifugal pumps to produce |
Head, not pressure |
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If there is too much of this acting on a centrifugal pump, it will overcome the ability of the pump to move fluid |
Back pressure |
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The pressure produced by a centrifugal pump is a relationship between quality of it manufacture and the |
Fluid being pumped |
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When used as a suction pump, the suction line must be equipped with a ______ ______ on it’s inlet |
Check valve |
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The check valve placed on the suction line is called a |
Foot valve |
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What device must be added to a pressure tank that does not have air/water separation |
Air volume control |
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The usual method to control a water supply pump is |
Pressure switch |
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Thermal overload is |
The frequent on/off cycle of the pump |
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The run cycle of the pump should be at least _____ min but not more than ______ times per hour |
2min 25 times |
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Centrifugal pumps are available in two general classifications |
Above ground In the well |
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Reciprocating pumps are essentially a |
Piston pump |
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Reciprocating pumps typically lift water from ________ wells |
Shallow |
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Electric piston pumps used as suction pumps come in two varieties |
Horizontal reciprocating pumps Deep well working head pumps |
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Single acting means the pump moves water out of the cylinder only |
When the piston moves in one direction |
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Double acting means the water moves out |
When the piston moves in either direction |
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Double acting cylinder is made with _____ chambers |
Two |
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What displacement are reciprocating pumps |
Positive |
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Because it is a positive displacement pump, it must be protected by |
Pressure relief valve |
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The pressure relief valve is usually set 15-20 pounds over the |
Pressure switch cut out |
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Reciprocating pumps are commonly used for |
Low production wells |
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To change a reciprocating suction pump to a deep well working head pump |
Move the piston into the well and connect it to the lifting mechanism with sucker rods |
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Diaphragm pumps are not |
Positive displacement |
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Diaphragm pumps must have a check valve on its |
Inlet and outlet |
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Bladder pumps keep mechanisms away from |
Fluids |
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Rotary pumps do not use impellers but is a |
Helical (screw like) shaft or meshing gears |
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Regenerative turbine pump is commonly used for |
Municipal water applications |
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Peristaltic pumps are similar to your heart and use a |
Squeezing action |
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A peristaltic valve uses a tube to squeeze fluid and the mechanism never |
Comes in contact with the fluid |
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A deep well turbine pump is |
Very large with very high pressure |
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Deep well turbine pump impellers are called |
Bowls |
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Deep well turbine pumps are often used for |
Irrigation |
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Jet pumps incorporate what into the inlet of the impeller |
A nozzle and venturi |
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The maximum depth of a jet pump is |
155ft |
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How many sizes smaller is the driveline than the suction line in a deep well jetted pump |
1 size |
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What creates the negative pressure on a jetted deep well pump |
Venturi |
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The water inlet on a jet pump may be extended by a long pipe of the same size, maximum |
35 ft |
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Submersible pumps use these to create pressure |
Stages |
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Each stage in a submersible pump increases pressure by |
9psi/stage |
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Submersible pumps for residential applications are typically _____ in dia. To fit into a 4in well |
3-5/8in |
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At what distance are submersible pump control wiring tied |
Every 10ft |
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Chemical feed pumps add chemicals to water in |
Measured doses |
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Sewage pumps commonly use what type of impeller |
Open impeller |
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Sump pumps commonly use what type of impeller |
Closed |
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The delivery capacity of a pump should closely match the amount of water available in the aquifer. If it cannot you can use a |
Flow control fitting |
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The 3 parts of a centrifugal pump diffuser are |
Turbine diffuser Impeller Diffuser cup |
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Pitless adapters must be purchased by |
The size of the casing |
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What may be added to the drop pipe to control flexing |
Torque arrestor |
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To properly size the drop pipe and supply pipe to the house requires detailed calculations of |
Pipe lengths Number of fittings Flow rate of system Elevation difference Desired pressure at point of delivery |
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Piping in a jetted pump must be _______ to start under positive suction head |
Primed |
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How is a pump able to lift water from a well |
By creating a partial vacuum in the pumping chamber |
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What condition may cause cavitation for a centrifugal pump |
Pump is working at maximum lift capacity |
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Why are centrifugal pump suction lines installed with positive grade from the pump to the well inlet |
For better air elimination when priming |
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How may drawdown in a well affect an aquifer |
Allow the aquifer to start releasing sand |
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Which piston pump can be offset from the top of a well |
Shallow well piston |
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Which pumps may produce enough pressure to damage a pressure system |
Reciprocating and submersible pumps |
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List the three types of impellers used in centrifugal pumps |
Closed Semi closed Open |