Pump Theory Flashcards
When pumping at a constant pressure, what is the quantity of water directly proportional to?
The speed of the pump (RPM)
When pumping a constant quantity (gpm), pressure is directly proportional to what?
The square of the speed
What is the equation to determine max pounds-gallons of a pump?
Max pounds-gallons = rated gpm x rated psi
LAFD pumps: 1500gpm x 150 psi =
225,000 pounds-gallons
What is the formula to determine GPM when the rated pump psi is exceeded?
GPM = max pounds-gallons divided by the new PSI
How is water in the volume of the pump prevented from returning back through the suction side of the pump?
Through the close fit of the impeller to the stationary wear ring at the eye of the impeller.
What happens when the pump wear rings are worn out?
The pump will fail to pump at it’s rated capacity and pressure.
What does an increase in rpm WITHOUT an increase in corresponding pressure indicate?
Increasing rpm without an increase in pressure indicates the pump is cavitating.
When checking the priming pump what amount of vacuum should be attained and what is the leak rate?
Prime should reach 22” and not lose more than 10” in 10 minutes.
In what amount of time should a prime be achieved before stopping and figuring out what is wrong?
30 seconds
What does an increase in rpm WITHOUT an increase in corresponding pressure indicate?
Increasing rpm without an increase in pressure indicates the pump is cavitating.
When checking the priming pump what amount of vacuum should be attained and what is the leak rate?
Prime should reach 22” and not lose more than 10” in 10 minutes.
In what amount of time should a prime be achieved before stopping and figuring out what is wrong?
30 seconds
