Glossary of Terms

A Glossary of Wells, Pumps and Simple Pump Terms

The following are brief descriptions only and are intended for someone with little to no knowledge of wells and pump terminology.




Drilled Well

Typically a 4-8 inch hole is drilled that will be a little larger than the casing. The casing is installed and the hole back-filled. A drilled well generally has the advantages of:
– Being less susceptible to pollution from surface sources because of the depth.
– And of being a more reliable water supply since it is less affected by seasonal weather than shallow wells.

Bored Well

Bored wells are typically 2 or 3 feet wide, although they can be wider. They are often used when low yielding groundwater sources are found relatively close to the surface. They are usually less than 100′ deep. Because the water source is low yielding, the wide well provides a reservoir of water to draw upon.
The well is drilled using a “rotary bucket auger”.

Dug Well

Usually these are old wells or wells found in developing nations. A hole is hand dug in the ground and lined with solid material such as brick, rocks or concrete culvert.
These days an excavator is sometimes used to dig the hole. Then a section of concrete culvert is placed vertically in the hole and the outside of the culvert is back filled.

Sleeve and Liner

Some wells have a narrower casing for most of their depth and a wider section near the top — maybe the last ten or twenty feet. The wider part is the sleeve. The narrower part is the liner.


The metal or PVC pipe that lines your well. Commonly 4, 5 or 6 inches inside diameter though you may sometimes find casing of 2, 4.5, 7 or 8 inches. The casing of a bored well will often be concrete.

Static Water Level or Water Level or Static

The distance from ground level down to the water at its stable level (i.e. not during or just after pumping). The static water level may vary somewhat from month to month and season to season.




The position of the pump in the well. E.g. “the submersible is set at one hundred feet” means the submersible is one hundred feet down in the well.

Pump Head

The part of the pump that is visible above ground.

Submersible Pump

An electrically driven pump situated down the well casing and in the water. The submersible pump pushes the water up to the surface.

Center Guides

These are often plastic or rubber devices that slip over, or snap onto, the drop pipe in order to center it inside the well casing. They also serve to hold the electrical cable close to the pipe and away from the casing wall.

Torque Arrestor

A flexible rubber or PVC device that may be mounted on the drop pipe a few feet above your submersible to prevent the pump from kicking or twisting with start-up torque. Otherwise the submersible pump may bang and twist against the wall of the well, eventually doing damage to the well, the pump, the drop pipe or the wiring harness that feeds electricity to the pump.

Jet Pump

The motor of a jet pump is situated above ground level. It pumps water through a narrow jet, creating a pressure differential that draws more water in and back to the surface.

Foot Valve

The name for the water inlet valve at the bottom of some types of hand pumps.

Well Caps

Well CAPS fit over the top of the casing similarly to how a lid fits over the top of a jar. There is overlap down the side and bolts hold the cap securely to the top of the casing.

Well Seals

Well SEALS consist of metal plates that sandwich a layer of rubber. As the plate bolts are tightened, closing the distance between the plates, the rubber seal is pushed out against the inside of the well casing and inwards around the outside of the pump discharge pipe.
There is also an opening for a 1/2″ air vent and an opening for the pump wire to be routed through the top.
These two terms, cap and seal, are sometimes used interchangeably. We like to keep the distinction between them as described above. All our well caps are well CAPS.

Drop Pipe

Drop pipe is the pipe that runs from the top of the well down to the pump. The three materials more commonly used in domestic wells are steel, PVC and high density polyethylene.

Pitless Adapter

A pitless adapter clamps to the side of the casing, and routes the water out through the side of the casing (rather than up through the top) in order to run underground.

The submersible drop pipe comes up from underneath and attaches to the bottom of the pitless adapter. Part of the pitless extends through a hole is the side of the casing where a lock nut then clamps it in position. A horizontal pipe attached to the pitless outside the casing and carries the water underground to the home. The pitless adapter is often used when winter conditions would freeze the water inside the pipe if the pipe exited from the top.

The “pitless” part of the name refers to the fact that these adapters did away with the older style of wells that used “pits”. A pit might be three or six feet wide and four or eight feet deep. The narrower well would then be in the floor of the pit. These pits had several disadvantages:
– Could be dangerous for children
– Could accumulate water leading to severe rusting and possible contamination
– Could house rodents
– Were inconvenient for servicing
– Were not as secure against frost.
On all these counts, a pitless adapter configuration is much superior.

Simple Pump has its own custom engineered pitless adapter that accommodates the need for the sucker rod to pass through the adapter on its way up to the pump head.

Pitless/Turtle/Clamshell Well Caps

This is a particular type of well cap used only with a pitless setup. There is no provision for the submersible pipe to exit through this type of well cap. The shape is circular with a bump on one side. The electrical wiring is routed through that bump-out and usually runs in a conduit down the side of the casing.

The turtle and clamshell names refer to to the fact that there are two halves with a space between.

Simple Pump has well caps of this style for 6″ and 6.25″ inside diameter well casings.

Pressure Discharge

The water being pumped from the submersible is under pressure. The pipe carrying the water out of the well is, therefore, sometimes referred to as the “pressure discharge” or “submersible discharge”. A pump’s discharge can either be through a pitless adapter or up through the well cap.

Check Valve

A valve allowing water flow in one direction only, usually towards your house while preventing the back-flow of water down the drop pipe and pump.

Coupling/Coupler/Butt Coupler

The coupler joins each length of submersible drop pipe. Steel or PVC are most common. Brass and galvanized couplings are sometimes used.



Pump Cylinder

Situated at the bottom of the system, at the end of the chain of drop pipes. With a piston and two valves, this is where the action happens, to lift your water to the surface.

Drop Pipe Kit

A “drop pipe kit” consists of our drop pipe plus the sucker rod that runs inside it plus a rod guide.

Sucker Rod

The rod inside the drop pipe that provides the mechanical connection between the handle or motor at the top and the piston inside the pump cylinder at the bottom.

Safety Tool

A U-shaped piece of machined aluminum with a beveled seat. The bell-end of our drop pipe sits securely in the bevel led seat during installation.

T-Handle Installation Tool

Screws into the top end of the topmost drop pipe for even more secure handling of longer (heavier) assemblies of drop pipes.

Pedestal Adapter

A flat plate with a circular rim which can be mounted on a 4″ well cap and is used to mount the Simple Pump to a wood, metal or concrete cover of a wide well.

Rod Extenders

A 1.25″ x 3/8″ steel extender for possible fine tuning of the total length of the chain of sucker rods.

Weep Hole

A 1/16″ hole drilling at 48 inches, or a custom length, down the top drop pipe. After the pump is used, the weep hole allows water to drain out of the pump head, preventing freezing. Or, in very hot climates, over-heating.

Seal Kit

A package of seals for the Simple Pump, usually consisting of two for the pump head and either two or three for the pump cylinder.


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