Do you want to be the ultimate Drip Irrigation DIYer? Then learn how to size the right pump the first time!



Q: What is friction loss?

A: Friction loss occurs as water moves through your tubing, pipes, and fittings. When friction loss occurs, pressure is reduced.


Q: How is friction loss determined?

A: With our friction loss calculator! Friction Loss Calculator

To convert the PSI to feet, you simply just multiply the number by 2.31


Q: What is Water Horsepower(WHP)?

A: Water horsepower refers to the minimum power required to run the pump.


Q: What is Total Dynamic Head (TDH)?

A: TDH is the vertical distance that liquid travels (in feet) plus(+) the friction loss from the pipe (in feet).


Q: What is GPM?

A: GPM is an acronym for the measurement of flow rate whichis cycling means “Gallons Per Minute” 


Q: What is the specific gravity of water (SG)?

A: The specific gravity of water is 1


Q. Is “bigger” always better when it comes to getting a pump?

A: No! Bigger is not better when it comes to irrigation pumps! If your pump is too big for the watering needs of your system cycling will occur and burn up your pump!


Q: What is cycling?

A: If the pressure is low in your system your pump is signaled to turn on. If the pressure is too high the pump is signaled to turn off. If you have too much water pumping through your system then water will return to the pump causing it to turn off. When pressure stabilizes again, the pump will turn back on. This is cycling and will quickly burn out your pump! 


Q. Do I size my pump to my system, or size my system to my pump? (What do I get first?)

A: Many would think that you should find a pump to build your irrigation system off of, but it is actually much easier to figure out all the details of your irrigation system first! If you can figure out what your specific watering needs are then you can find a pump to fit your needs.


Q: How do I determine what pump I need? (what info)

A: Use our helpful Pump Worksheet! Once you figure out your numbers use our Pump Selection Chart!


Q. What is the difference between an irrigation pump and a water-transfer pump? How can I tell the difference?

A: Irrigation pumps are designed to move water while producing pressure and flow rate to ensure that your water makes it to the desired location. While water-transfer pumps are also designed to move water, they do not produce pressure or flow rate at a rate sufficient enough for irrigation. When purchasing a pump, if the measure of flow rate used is GPH then that pump is a water-transfer pump. If the measurement used is GPM, then you are in the right place and have found an irrigation pump!


Q: How does elevation change affect my pump selection?

A: If your pump sits above your water source, you will need to account for the amount of suction lift (in feet) that your pump will have to do. Suction lift is the vertical distance from your pump to the water level. If your pump is below the area that you plan to water, then you must measure the distance from your pump to the highest point that water will have to reach. Then add these numbers together for your total elevation change. 


Q: What is loss of Prime?

A: The water inside an above ground pump has been lost with water in the piping between the pump and well. Here is a video from Munro about this: https://youtu.be/f3VcGUMUm0o


Q: What is Cavitation?

A: When bubbles or voids form within fluid because the pressure quickly drops below the vapor pressure. The bubbles then collapse causing small shock waves that over time, will damage components of the pump. When these pressure waves punch holes into parts it is called "pitting. Cavitation sounds like tiny rocks are in the pump. Here is a video from Munro on this: https://youtu.be/BOgUyXVAGu8https://youtu.be/BOgUyXVAGu8

Check out these helpful pump resources from our website!


Here are more helpful videos by Munro: https://www.munropump.com/Resources/Videos 


Don't forget to check out our video on how to size a pump!: 




Still, have questions? Feel free to reach out to our wonderful and knowledgeable Customer Service team! Help Desk