Pumps Flashcards
A pump is a device that?
Creates a pressure difference in a fluid
What is the difference between a pump and a circulator?
The true pump drive motor is larger than a circulator pump of the same volume
List the 4 components of a pump
- Impeller
- Casing (with a volute discharge)
- Shaft
- Seal
Three parts of an impeller
- Eye
- Vanes
- Disk
How does the volute change fluid pressure into static pressure?
By forcing water through an increasing cross sectional area of the volute channel. As channel size increases, velocity pressure decreases and static increases.
What are the 2 categories of pump seals?
Mechanical and packed
Do mechanical seals weep liquid?
No
Where does the lantern ring get its lubrication from?
The flushing tube takes some pumped liquid to the lantern ring that distributes the liquid into the seal packing rings where it cools and lubricates the seal packing
What happens to the liquid that cools a packed seal?
It drains through the threaded connection on the bottom of the bracket
How is proper bearing greasing accomplished?
By removing the relief plug before adding new grease through the fitting. The relief plug is replaced only when new grease is forced out of the relief plug orifice.
Is the pump running during hydrostatic processes?
No
What is the weight of a column of water?
2.31 ft/psi
How do we convert psi knowing pumping head and the specific gravity of any fluid?
PSI = (head x sg)/2.31
Pump affinity law #1
Pump RPM and volume are directly proportional
Simplified formula for Bernoulli’s theorem?
Pressure total = Velocity pressure + Static pressure + friction losses + gravity losses/gains
