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Welcome to Inspector Pumphead’s Frequently Asked Questions! I will be answering some of the most common questions we get on a specific topic. Some of this information may also be available elsewhere, but this feature will serve as a convenient one-stop source. In this edition, I’ll talk about well pumps.

Well Pump FAQ

1. Why are there two different types of well pumps listed? What’s the difference between ‘jet’ and ‘submersible?’

Jet well pumps are surface pumps configured above the well system, while a jet assembly system (twin pipe or Packer depending on the application) is inserted into the well shaft. The main components of a jet pump are a nozzle, venturi and the jet itself. The physics and mechanics of it are interesting, but we’ll focus on the basics here: these components work together to create a vacuum above the water, which allows atmospheric pressure underneath to push the water upwards.

Jet pumps can be either horizontally or vertically configured and are much the same size and shape as other pumps.

Submersible well pumps are actually installed and submerged under water at the base of the well. Whereas jet pumps use suction to pull water, submersible pumps create pressure to push the water in an upward direction. Submersible well pumps are cylindrical and “thin” in diameter so as to easily fit down a well shaft. They are often tall as well since submersible well pumps usually contain multiple stages stacked on top of each other. A stage is simply a compartment with an impeller, diffuser and upthrust washer that increases the pressure as water moves up through each stage. The more stages, the higher the head.

2. So which one is better?

As is always the case when it comes to pumps, the answer is “it depends on your system and application.” Submersible pumps are more efficient, especially in deeper wells. The farther the pump is away from the water table, the less effective it will be. Since submersible well pumps are closer to the source, they are more reliable. The downside to a submersible pump is that it must be pulled out for maintenance, repair or replacement. Being submerged also exposes the pump to contaminants such as sand.

3. What constitutes a ‘deep well’ or ‘shallow well?’

The depth of the well refers specifically to the depth of the water table, which is the top of the reservoir. A water table 25 ft. or fewer underground, while any water table deeper than 25 ft. is considered a deep well.

4. What is a convertible jet pump?

A convertible jet pump is a pump that can be configured for either shallow well or deep well applications with the proper fittings. Convertible jet pumps are often built as deep well jet pumps and include a bolt on shallow well adapter. Deep well fittings, such as the jet assembly (twin pipe or Packer) are usually purchased separately.

5. Why would I need a convertible pump? Shouldn’t I just get either a deep well or shallow well pump?

Usually you’d be able to stick with either one or the other type of jet well pump. In some areas, however, water tables may fluctuate due to the climate, unique elevation, topography changes or other factors. A convertible jet well pump ensures that you will be prepared and will continue to receive well water in such a case.

Pump Products application engineers are standing by to help you find the right pump, as well as to provide price quotes, availability and shipping information. Call our toll free number 1-800-429-0800.