A well pump is a broad term for any pump that is used to pull water up from a well. Water well pumps are not intended for continuous use. They are, however, able to provide continuous pressure by moving the well water to a storage tank, which contains an air bladder that regulates the air pressure within the tank; as water is pumped in, the bladder is compressed, increasing the air pressure. It is the air pressure that moves the water through the plumbing.
There are three types of well pumps: shallow well pumps, convertible pumps, and deep well pumps. The distinction between these pumps lies in the vertical distance they are designed to move ground water. A shallow well jet pump is a non-submersible pump that is used when the water has to be moved a small vertical distance, usually no greater than 25 feet. A deep well pump, on the other hand, is intended for wells where the water must be moved a distance of up to 80-90 feet; some can handle distances of up to 1000 feet and more. Deep well pumps are also fully submersible for that reason. A convertible pump is simply a shallow well pump with a removable ejector kit, which allows the shallow well pump to be transformed into a deep well pump, which can then be used to carry water between 25 and 80 feet. This conversion is accomplished by taking the removed ejector kit and placing it within the well itself, underneath the water level. The convertible pump, however, is not submersible, and must still be installed above ground.
A shallow well pump is installed above the well- either within the home or in a separate well house. This pump is meant to extract water from a well by creating a vacuum, where the weight of the air will force the water up through a tube lowered into the well. Due to this design, it is the weight of the air that determines how high the water can be lifted, so the exact distance may vary slightly with elevation, but most shallow well pumps are rated for approximately 25 feet of vertical lift. A shallow well jet pump is used to
It may be necessary to include a tailpipe of approximately 35 feet in length in the convertible pump installation, so as to prevent overpumping. The tailpipe should be connected to the pump intake and lowered into the well. In this way, it the water level drops below the jet, the convertible pump would continue to operate as a regular shallow well pump. However, it should be noted that the further the jet is from the water, the less efficient the pump will be. For pumping groundwater that is deeper than 25 feet, it may be convenient to convert a shallow
Submersible well pumps are constructed differently from regular well pumps, as the motor needs to be sealed tightly so as not to become flooded. Typically, the pump features a well casing and a hermetic seal. Submersible pumps also usually have a series of stacked impellers, which are separated by a diffuser; this mechanism is what drives the well water up the pipe, unlike the vacuum suction method used by shallow well pumps. For transporting water large vertical distances, the use of a submersible pump may be