Inline – Top Deep Well Pump Basics

Use the Inline - Top Deep Well Pump System if your well specs meet one of these scenarios:

Static Water Level:160′ or less
Electric Submersible Pump Installed:Yes
Well Casing Outside Diameter:4″ or less
Freezing is an Issue:No
Static Water Level:160′ or less
Electric Submersible Pump Installed:Yes
Well Casing Outside Diameter:5″ or more
Well has a Liner:Yes
Freezing is an Issue:No


The Bison Pumps Inline – Top Deep Well Pump System is a stacked pump system (Stacked Deep Well Pump Basics) that installs in the same well casing as your electric submersible pump system. It is not a Freeze Proof pump system. It can deliver you with Pressurized Backup Water through your existing water line. This is possible when you operate the manual hand pump but leave the shut-off valves set for the electric submersible pump operation. This provides you with water inside your home accessible to any water feature such as a toilet or sink. This system can lift water from 160 feet deep. An Inline – Top Deep Well Pump System is recommended when there is not sufficient space for the Bison Pumps Side-By-Side Deep Well Pump System and an electric submersible pump system to be installed inside the well casing/liner.

Inline Deep Well Pump Adapter

The Bison Pumps Inline – Top Deep Well Pump System with the Standard Deep Well Pump Adapter welded on is used for this pump system. It connects directly to the electric submersible pump’s pipe. The electric pump’s water outlet is on the body of the Inline – Top pump head. This outlet is above ground therefore the Top designation. This means that the water outlet from the electric submersible pump is subject to freezing if exposed to the elements. Therefore, we only recommend this pump system if the freezing issue is addressed by the owner.

Additionally, this outlet must have a shut-off valve attached between the outlet and the owner’s water pipe. Bison Pumps offers an Inline – Top Electric Submersible Pump Outlet Connection Shut-off Valve Assembly for that purpose.

Well Pump Adapter

This system works with well casing diameters from 4” up to 8” (special order above that size).

Top View of Inline Deep Well Pump Adapter

The well pump adapter replaces your well cap and provides a seal to protect your well water from contaminants. The adapter has one 3/4” NPT threaded port for wires from an electric submersible pump to exit the well. Another port, 1/2” NPT (3/4” if pump is installed in Michigan) is for the Vent Plug. There are four bolt holes for the bolts that hold the bottom plate kit to the well pump adapter.

The bottom plate kit shown below provides the seal for the well. It consists of a rubber gasket and stainless-steel bottom plate. The rubber gasket is compressed by the bottom plate when the four bolts that are attached to it and the well pump adapter are tightened.

Bottom Plate Kit
Rubber Gasket Compressed by Bottom Plate

This gasket can expand up to 1/4” to create a seal. Therefore, we must resize the gasket for every 1/4” change in the inside diameter of the well casing. This is why it is so important to provide us with an accurate inside diameter measurement. 

Wires from your electric submersible pump must exit the well. They can exit either through the side of the well casing if permitted in your area. If not, then the wires can exit through the port hole provided in the top of the well adapter. Bison Pumps offers a conduit system for either approach: Conduit El – Top Mount or Conduit El – Side Mount.

Socket-Set Point Cups and Covers

Each well adapter covers a range of outside diameters of the well casing, for example the 6” covers from just below 6” to just over 7” in diameter. Four all-thread Socket Set-Cup Points with Covers are provided to address these size differences. When the well pump adapter is mounted to the well casing, you will thread the bolts through the four holes provided in the side of the adapter. These will apply pressure against the well casing providing more stability for the pump head. Plastic covers are provided to protect the all-thread Socket Set-Cups.

Additionally, to further protect your investment we can add a Tamper Proof Kit system to this style of well adapter. The well pump adapter will be connected directly to the well casing with security bolts. This system protects against unwanted removal of the pump head.

Drop Pipe and Rod

Each Bison Pumps Stacked Inline – Top Deep Well Pump System comes with enough eight (8) foot sections of Drop Pipe and Rod to reach approximately 20 feet below the static water level. This depth allows for fluctuations in the water table and ensures that the cylinder will be below the water surface. The size of the Drop Pipe is typically 1 1/4” NPT.

Note that the deeper the static water level is, the more drop pipe will be required. This directly impacts the cost and design of the system. This is why a fixed cost for a pump system cannot be provided. Each pump system is unique to the customer’s well specifics.


One appropriately sized cylinder is included in a Stacked pump system. In a Lift Pump system, like the Stacked, the actual “pump” is the cylinder. This is the device that creates the vacuum to draw water into the water inlet and then uses its piston assembly to lift the water up the drop pipe. In a Stacked application, the size of the cylinder is determined by the static water level and the GPM of the electric submersible pump. We use this Stacked Cylinder Selection Chart to determine the appropriate size based on the static water level.

Stacked Cylinders are enclosed in a protective cage to prevent the weight of the electric submersible pump from pulling it apart. The diameter of this cage is approximately 3 inches. Therefore, that defines the minimum inside casing diameter in which this pump system can be installed.