What Is a Submersible Pump and How Does It Work?


Living in the country has its advantages. Country living is quieter, there’s less traffic, and more chance to enjoy nature’s beauty. But, of course, living without being connected to municipal water goes with the territory, too. 

That means having a private well, like 13 million households in the US do. We all take getting water out of the tap for granted. But how does that water get to your house? That’s where a submersible pump comes in. What is a submersible pump? How does a submersible pump work? 

Let’s take a look at the basics of a submersible water pump.

What is a Submersible Pump?

Any time you need to submerge a pump in whatever liquid it’s pumping, you’ll be using a submersible pump. It’s that simple. Most of us are familiar with submersible water pumps – sump pumps, well water pumps, and sewage pumps – the kinds of pumps we see at home. 

Like this Franklin electric submersible pump, a submersible pump is down in your well, pushing the water out and up to your faucet.

Specialized submersible pumps are also widely used in mining, dredging, sewage treatment, and the oil and chemical industries. No matter the application, all submersible pumps operate on the same principle.

So How do They Work?

Submersible pumps use a hermetically sealed motor with a water-tight enclosure – often oil-filled – around it. That prevents short circuits – very important since electricity and water don’t play well/

Submerging the pump in water creates positive pressure at the inlet, which means greater efficiency (less energy required) to move the water through the pump.

The pumps take advantage of the head pressure by pushing, not pulling, the water, adding to their efficiency. In addition, cooling submersible pumps isn’t an issue since the water around them keeps them cool.

How to Choose a Submersible Pump

Choosing a submersible sump pump is straightforward. However, picking the right pump for your well is a bit more complicated. The two primary considerations are how deep the well is – and home wells can range from 500 feet or more down to 20 feet – and how much flow you need.

Flow is measured in gallons per minute. Another consideration is how much pressure (PSI) is required. 

Here’s an example of how that comes together. Jack needs to pump water at five GPM from his 300 foot deep well up to the house, which is 85 feet above the wellhead. So he needs a five GPM with 500′ of head (216 PSI).

If all of that seems too complicated, the best advice is to ask the experienced folks at a pump supply store for their recommendations. After giving them some basic information, they’ll be able to spec the perfect pump for your situation.

Submersible Pumps are Simple, Right?

Now that you know a little more about what a submersible pump is and how it works, if the time comes when you need to buy or replace a submersible pump, you’ll have the water flowing in no time!

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