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72 Cards in this Set
- Front
- Back
- 3rd side (hint)
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What is a pitiless adapter? |
Corrosion resistant Adapter used to allow transition from vertical piping to horizontal. Installed below the frost line. |
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Pumps create a negative pressure at the inlet side of the pump, which allows atmospheric pressure to force water into the suction line. When a pump creates suction this results in a pressure that is less than atmospheric. If a vacuum is created at 1 psi, how high can the water be lifted? |
2.31 feet |
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If a vacuum is created at -14.7 psi, how can can water be lifted? This is called a theoretical lift |
33.8 feet |
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Most pumps can at best create a negative pressure at about -58psi. How high can the water be lifted? |
25 feet |
58/2.31= |
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For every 1000 feet of elevation, how much less can a pump be expected to lift? |
1 foot |
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Centrifugal pumps must be primed ( filled the pump with water, displacing all air from the suction side). Why is this important? |
Impellers cannot create the vacuum required to pull water if there is air in pump |
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In a deep well, what else needs to be filled with water? |
Suction and drive lines |
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What is the purpose of bobbing the pipe? |
It fills the pipe with water |
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Once primed, the spinning action of the impeller causes the water to fly off the end of the vanes at very high speed. This creates a vacuum at the eye, allowing what? |
Atmospheric pressure to push more water into the impeller, so the pump sucks or pulls water into the pump. |
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To build pressure on the discharge side of the pump, we must slow down the high speed water from the vanes of the impeller and slow it down. How is this achieved ? |
Using either a volute or a diffuser installed around the impeller. They gradually widen the high speed waters path , slowing it down and building discharge pressure |
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Multiple impellers can be used to add pressure. They do not however increase _________ |
Flow rate ( gpm) |
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What are closed impellers used for? |
Clear water only |
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What are semi closed impellers used for? |
Weeping tile sumps or any application with small bits of dirt that will pass through |
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What are open impellers used for? |
Sewage. The impeller can chew up larger chunks of solids and pass through the pump |
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What is cavitation as it applies to pumps? |
When water is in a state of reduced pressure, it’s boiling temp is reduced. A spinning impeller creates a negative vacuum. With water gaining heat in a partial vacuum it will start to boil in the pump casing. This is called cavitation |
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Why does slippage occur through an impeller/diffuser assembly ‘tolerance’ ? |
If the discharge is slightly blocked or the the pump is trying to push water higher than it it is designed for, slippage back into the pump may occur |
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When the water or slippage sits in the pump assembly it does not move . When it heats up and boils, ( cavitation)what else heats up? |
The pump and motor. |
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A pump that is cavitating sounds like what? |
Gravel is moving through it |
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How to avoid cavitation? |
Properly size the pump, ensure no restrictions in the inlet side of the suction line, no throttling valves |
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Cycling the pump, Frequent on/off cycles , cause wear and tear to the motor and seals. How is this prevented? |
Run cycles should be no less than 2 minutes long to ensure the pump has dissipated all the waste heat from the motor. The pump should cycle no more than 25 times per hour. |
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the pressure switch must be set for a differential between the cut in and cut out pressures of ______psi. |
20 psi. Usually a 20/40 cut in/cut out |
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Pressure tanks must have enough usable water that the pump doesn’t turn on every time someone flushed the toilets. This prevents undue ______ |
Cycling of the pump |
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Why don’t centrifugal pumps like air, or gas? |
Air or gas cause airlocks or loss of prime in the pump |
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What pump is best for water with air gas or sand in it? |
Piston pump |
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What is a submersible pump? |
Pump with a Fully enclosed water sealed motor |
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How does a submersible pump work? |
Water enters a screened inlet above the motor, drawn into pump through a vacuum created by lowest impeller |
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Most submersible pumps are ____” inside a ____” casing |
3 5/8” 4” |
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Impeller diffuser assemblies are stacked in Stages. What is each stage capable of producing? |
9psi |
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Jet pumps in basements require suction to pull water up from wells or cisterns. What is added to aid the impeller or diffuser? |
A Venturi assembly , aka jet assembly or ejector |
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Venturis send some discharge water back down the suction line through an Orifice . As the water picks up speed it creates a more efficient ________behind it. |
Vacuum |
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Venturis mounted on the pump in the basement have the ability to pull water up from depths of ______ft |
25 feet |
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If Venturi are mounted deep in the well they can the point of suction is deep in the well. If it can pull water 25 feet, what happens if we install it 155 feet in the well? |
It can pull water from 180 feet deep. |
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Deep well jet pumps require a 2 pipe system. These pipes are known as the _______ and ______. |
Drive line Suction line |
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Driveline is __________than the suction line. Typically,______ |
One pipe size smaller Driveline 1” Suction line 1 1/4” |
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With 2 pipes going down the well, a two pipe _________ is required. |
Pitiless adapter |
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Tailpieces , typically 35’, is added to an ejector to avoid ________. |
Over pumping |
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What is used at the suction inlet end of suction lines or tail pipes to avoid air and ensure the line is full of water? |
A check valve with an inlet screen called a foot valve |
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Where is the Venturi assembly located on a shallow well Jet pump? |
On the pump in the basement |
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Where is the Venturi assembly installed on a deep well pump? |
Deep In the well |
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In line circulation pumps do not require head pressure, ejectors or multiple impellers because it is a closed system. All that is required is an impeller and volute. What must be taken into account when sizing a circulation pump? |
Friction loss |
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Booster pumps are mounted _______. They are designed using multiple impellers to move water __________ |
In line Up multiple floors of a high rise building |
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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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How does the diameter of the well affect pumping capacity? |
By limiting the size of pump you can install |
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What is the maximum theoretical lift of a centrifugal pump used as a suction pump ? |
Close to 34 feet |
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Why is a jet pump capable of greater suction than a centrifugal pump? |
Jet pumps are better at creating a negative pressure |
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How does friction loss affect the use of a suction pump? |
By reducing amount of work done by atmospheric pressure |
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What condition may cause cavitation for a centrifugal pump? |
Pump working at max lift capacity |
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Why are centrifugal pump suction lines installed with a positive grade from the well to the pump inlet? |
Better air elimination when priming |
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How May drawdown in a well affect an aquifer? |
Drawdown can allow the aquifer to start releasing sand |
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Why should pump capacity be matched to well capacity? |
To prevent aquifer problems from developing |
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When is a well considered a deep well? |
Deeper than 24 feet |
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Which piston pump can be offset from the top of a well? A deep well piston or a shallow well piston? |
Shallow well |
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Which pumps may produce enough pressure to damage a system? |
Reciprocating and submersible pumps |
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What are helical screw pumps usually used for? |
Pumping slurries and sludges |
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When a shut off valve is placed on a tank tee for residential installation, which side of the tank tee should it be placed on? |
Outlet of tank tee |
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Why does a submersible pump require a check valve at its outlet? |
To stop water from draining out of the drop pipe through the pump |
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What types of impellers are used on centrifugal pumps? |
Closed, semi closed, open |
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What device is used on the outlet of the two pipe jet pumps to allow the pump to produce the most water possible? |
Flow control fitting or valve |
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Slots or screens at the bottom of the casing are to _______ |
Keep out sand or gravel |
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What purpose does the foot valve serve on a drop pipe? |
Keeps drop pipe full of water |
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What is an aquifer? |
Underground sand/gravel that contains water |
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What are pump capacities generally rated in? |
Gallons per minute |
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What is the purpose of a sanitary well seal? |
To keep contaminates from entering well |
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Jet pumps are adapted centrifugal pumps that incorporate a nozzle and what other feature? |
A Venturi assembly |
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What causes a float type air volume control to work? |
Water level in the pressure tank |
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What is the definition of pressure drop in a pumping system? |
Loss of pressure caused by friction of the water in pipes, fittings and equipment |
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On pressure systems when a pressure tank is at its cutout pressure it contains _____% of air |
33% |
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What needs to be placed on the outlet of a submersible pump to prevent reverse rotation of the pump? |
A lift check valve |
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What is the device that lets in atmospheric air to the pressure tank called? |
The air volume control |
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In deep well turbine pumps, what are the sections that house impellers called? |
Bowl sections |
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In chemical feed systems, what advantage do pumps have over chemical pot feeders? |
Accuracy |
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When wells go beyond 300 ft what material is used for the drop pipe? |
Polyethylene series 160 |
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