Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
30 Cards in this Set
- Front
- Back
|
True or False. In a closed system, as the velocity energy increases, the pressure energy decreases. |
True. |
|
|
What occurs in a pump when a liquid vaporizes in a closed system? |
Cavitation Occurs. |
|
|
True or false. All positive displacement pumps have a pumping chamber? |
True. |
|
|
True or false. Positive displacement pumps cannot handle entrained air? |
False. |
|
|
True or false. Double acting piston pumps discharge an equal amount of liquid on all strokes? |
False |
|
|
Which one of the reciprocating pumps can be allowed to run dry? |
Diaphragm pump |
|
|
True or false. Rotary pumps produce a smother flow than reciprocating pumps? |
True. |
|
|
What is the definition of absolute pressure? |
Gauge pressure plus atmospheric pressure. |
|
|
An increase in liquid velocity can cause what to occur? |
Cavitation |
|
|
True or False. When the pump inlet is above the level of liquid in the supply reservoir, the pump has a suction head? |
False. |
|
|
What is the relative density of water? |
Back (Definition) |
|
|
What source of energy is available to allow liquid to enter a pump with suction lift. |
Atmospheric pressure. |
|
|
What pump component converts mechanical energy into kinetic energy. |
Impeller. |
|
|
Who provides us with pump curves. |
The pump manufacturers |
|
|
Unless other wise stated, pump performance curves are based on handling of what? |
Cold water. |
|
|
When you have a safe work permit to service a pump, what is the first thing you must do before commencing work |
Isolate the pumps prime mover. ( tagged and locked out.). |
|
|
The coupling between the drive motor and the pump shaft is usually made of a? |
Flexible style of coupling. |
|
|
What are the two types of pumps? |
Positive displacement pumps. &. Variable displacement pumps. |
|
|
The three types of reciprocating pumps are? |
Plunger pumps Piston pumps & Diaphragm pumps |
|
|
The membrane of what pump. Completely isolated and seals the pumped liquid from the rest of the pump and makes it suitable for use with toxic and hazardous liquids. |
Diaphragm pump. |
|
|
Are all rotary pumps deliver a much smoother flow than reciprocating pumps |
Back (Definition) Yes |
|
|
Name the 4 types of variable displacement pumps. |
Centrifugal or radial pumps Mixed flow pumps Axial flow pumps Peripheral flow pump. |
|
|
Of all the variable displacement pumps which two are most often used in the heating and cooling industry. |
Centrifugal or radial flow pump Axial flow pump. |
|
|
What is the most common type of variable displacement pump used in the industry. |
Centrifugal pump. |
|
|
What can affect the density of a fluid. |
Temperature |
|
|
What is the most common type of variable displacement pump used in the industry. |
Centrifugal pump. |
|
|
What can affect the density of a fluid. |
Temperature |
|
|
Most pump manufacturers rate their pumping capacities at "blank" suction lift |
15 ft |
|
|
The NPSHA in the system should be at least "blank" greater than the NPSHR in order to prevent cavitation from occurring. |
10% greater. |
|
|
In order to properly select the pump, you must calculate: |
The total head loss of the piping. The required flow(gpm) of the system. |
