How a Grundfos SQ pump proved to be a perfect replacement pump

Find out how an American well driller company benefitted by replacing a conventional submersible pump with a Grundfos SQ submersible pump and learn about the applications in which an SQ/SQE pump is an ideal solution.

When it comes to groundwater supply, the Grundfos SQ submersible pump range is the right choice.


In the first part of this module, we’re going to focus on a specific case in which the American company, Partridge Well Drilling, took a conventional 4” pump and replaced it with a 3” SQ submersible pump.


At the end of the module, we’ll introduce you to the various applications in which the Grundfos SQ submersible pump range can be used. For now, though, let’s turn our attention to the case story in America."

So, today we are at a new construction site where they installed a 4" submersible pump and a 4" artesian well, and they weren't happy with the performance, so we came out and did some analysing and decided to go with a 3" submersible SQ Grundfos pump.

It's going to provide a couple of things: home supply, domestic use, it will supply the irrigation for the property. There's a lot of thing we consider before we run step flow on site, to make sure we are getting the best application possible for our customer.

How the well is constructed, the demand of the system, what the customer needs, what gallons per minute and pressure they're looking to get it delivered at.

The Grundfos SQ pump can be used in any application for groundwater supply. Whether it would be residential, commercial, agricultural irrigation, within the flow range of the pump itself, which is essentially 5 gallons per minute up to 30 gallons per minute.

The SQ pump has a number of advantanges over a traditional 4" pump. The use of a permanent magnet, electronially controlled motor. This motor runs at 10.700 RPM. So, it allows us to use a smaller diameter impeller and still provide the water pressure and flow that we need, from the 3" pump to match the performance of traditional 4" pumps.

Along with that, we got built-in motor protection in the electronic device, to protect the motor from over voltage, under voltage, overload and underload. It also allows us to have a soft start feature in the motor, where the motor ramps up slowly when power is applied to it. This provides for low starting current draw on the motor, which allows us to use a smaller diameter wire, to run the pump of the same horsepower as a 4" pump.

Because it is lighter weight, the wire size is a little smaller, it can be installed in a 3" diameter well, which is genereally less expensive to install, so there can be some very good finacial benefits as well.

Today, we pulled a 4" submersible pump out of the well and replaced it with a 3" 22 SQ submersible pump. Took about an hour to do that, maybe a little less. But we think it's going to be a good application for this homeowner here.

There's a lot of reasons we enjoy putting these products in for our customers. It's very easy for us to install so it keeps the cost down for a customer. Another reason is the quality of the product. It's a long lasting pump that our customers will be able to enjoy for many years. Keeps the service rates down and the cost down for them and it's a pump that really performs well under many applications.

So, as demonstrated here, applying a Grundfos SQ submersible pump in domestic water supply brings benefits aplenty – both for the installer and the homeowner. But domestic water supply isn’t the only application in which the SQ performs well. In the second part of this module, we’re going to introduce you to a number of other applications in which an SQ is ideal.

As we’ve just seen, it can be used in domestic water supply. Along with irrigation, these are the two most common applications.

However, it can also be used to lower the groundwater level. This is often applied during the building and construction phase if the groundwater level is too high. In any case, the SQ helps to ensure that the soil around the construction site is dry.

Next up, it can be used in ‘ATES’ – or Aquifer Thermal Energy Storage systems. Briefly put, ATES is applied when cooling and heating is provided to households by means of extracting and injecting groundwater.

The SQ can also pump aggressive water such as saltwater concentrations of up to 2000 parts per million at +5, and up to 1100 parts per million at +20. Such content makes the water very aggressive towards the pump materials, so, in order to prevent corrosion, it’s recommended that the more corrosive-resistant SQ-N or the SQE-N pumps are used.

So, that covers all the applications in which you can use a Grundfos SQ submersible pump. Let’s recap what we’ve learned in this module.

First of all, it offers built-in motor protection to protect from over/under voltage and over/underload and soft start.

It’s easy, quick and cheap to install and it fits both in 3” bore holes and larger wells.

It’s a high-quality, long-lasting pump ensuring a reduced service rate and better reliability.

Finally, the Grundfos SQ submersible pump range can be used in a variety of applications including:

-Domestic water supply


-Groundwater lowering


Aquifer Thermal Energy Storage

-Pumping aggressive water

-And the dewatering of contaminated water, once again demonstrating the flexibility and versatility of the SQ pump range.

Course overview

Modules: 7
Completion time
Completion time: 40 minutes
Difficulty level
Difficulty level: Intermediate