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;
21 Cards in this Set
- Front
- Back
Disadvantages of centrifugal pumps
|
lack of suction lift
|
|
Deflector (Flinger)
|
a flange or collar around a shaft which rotates with it to prevent passage of liquid along the shaft
|
|
Diffuser
|
A piece, adjacent to the impeller exit, which has passages for converting velocity to pressure
|
|
Casing Wearing Ring
|
a replaceable ring to protect leaking between casing and impeller
|
|
Lantern Ring
|
used to establish a liquid seal around shaft, lubricate stuffing box packing, prevent air into stuffing box
|
|
Volute
|
The expanding spiral case
|
|
Overspeed trips are set at...
|
110% of normal operating speed
|
|
Unloading valve
|
valve located downstream of the pumps discharge to regulate and maintain system pressure
|
|
Rotary pumps are...
|
positive displacement pumps
|
|
Advantages of rotary punps
|
self priming
high suction lift low maintenance |
|
Reciprocating pumps are...
|
positive displacement pumps
|
|
Mechanical seal
|
prevents liquid or gas in or out of the pump casing
|
|
Mechanical seals are not used on....
|
centrifugal pumps (lack of lubricating liquid)
|
|
After 30 minute run-in period of mechanical seal...
|
no visible seal leakage is expected
|
|
Mechanical seal should be replaced if...
|
more than 5 drops per minute occurs
|
|
Do not use petroleum jelly,TFE, or silicone grease on an.....
|
elastomer seal
|
|
Packing on pumps in use with flammable liquid should maintain a leak rate of...
|
1 to 5 drops per minute
|
|
Stagger packing rings....
|
90 degrees
|
|
Hot alignment
|
-when unit is aligned at operating temperature
-motor driven units must be run a minimum of 4 hours to get operatimg temperature |
|
Physical adjustments should not be taken until the unit....
|
has cooled to room temperature
|
|
Hot alignment readings taken within....
|
30 minutes of shutting down machinery
|