Irrigation Pumps

A dependable pump is necessary to provide water to your irrigation sprinkler heads

Irrigation Pumps

Irrigation pumps are sometimes an overlooked part of irrigation systems, but it’s a very important part as the pump is responsible for getting the water to the sprinkler heads. They are available in different designs with different technical features, such as capacity, power and efficiency.

This buying guide highlights the different types of irrigation pumps, along with their performance and installation considerations.

Types

There are four basic types of irrigation pumps: Surface centrifugal, submersible, turbine and propeller

  • Surface centrifugal pumps installed above the water level are the most commonly used pump. They must be filed with water, or primed, prior to operation and can draw water from reservoirs, lakes, streams and wells, but their efficiency and capacity may be somewhat limited compared to other types.
  • Submersible pumps are installed completely underwater, motor and all. They tend to operate with greater efficiency as they are constructed with either dry motors, where water cannot get into it, or with wet motors where the motor functions normally despite water running through.
  • Turbine/jet pumps are a combination of surface and submersible pumps, as they feature a submerged pump and surface motor. They are good for locations where the surface of the water supply fluctuates because they can use suction to bring water up, adding to their versatility with high capacity performance with low-pressure levels.
  • Propeller pumps may be axial or mixed flow and are used with installations where the pump is located fairly close to the surface of the water supply and needs to generate a high flow rate. They don’t produce high pressure, but they do provide high capacity.

Pump Type Benefits Points to consider

Propeller

  • Simple construction
  • Don't need to be primed
  • Portable
  • Cannot generate suction to lift water
  • Provide low energy output

Submersible

  • Enclosed impellers maximize efficiency
  • Don't need to be primed
  • Easy to install
  • May be less economical
  • Ideal for booster applications
  • Can only be powered by electricity
  • Susceptible to lightning strikes

Surface Centrifugal

  • Economical
  • Easy to install
  • Constant flow rate
  • Offer a wide range of different capacities
  • Need to be primed
  • Must be located fairly close to the surface of water supply
  • Losing prime may result in pump damage

Turbine/Jet

  • Operate quietly
  • Don't need to be primed
  • May be used in wells
  • May be used in conditions where water depth changes
  • Less economical
  • May be more difficult to install, inspect and repair
  • Require periodic impeller adjustments to maintain efficiency

Performance and Winterization

Performance is measured in capacity, flow rate and pressure

  • Capacity is measured in gallons per minute (GPM) and is a function of the motor’s horsepower, discharge pressure and the distance above the water the pump is located.
  • Try to find the proper balance between flow rate and pressure.
  • Keep in mind as the flow rate increases, pressure decreases and vice versa.
  • Try to avoid long runs of pipe as they tend to reduce efficiency.
  • Larger pumps and impellers with smooth finishes tend to operate with greater efficiency.
  • If you live in a climate with temperatures below freezing, you’ll need to winterize the system by disconnecting the suction and discharge lines connected to the pump, emptying water from all pipes and storing the pump indoors during the cold season.