Does a Simple Pump fit in a 4” Well with a Submersible and Pitless Adaptor?

A Simple Pump can fit in a 4" well with a pitless adapter, though maneuvering or replacing the adapter with a slimmer version may be necessary for installation.

Simple Pump Team
9/18/2025
3 min read

Installing a Simple Pump alongside an existing submersible pump in a 4-inch well requires careful consideration of space constraints. Here's what you need to know.

Space Requirements

Simple Pump Components

  • Drop pipe: 1" Schedule 80 PVC (1.315" OD)
  • Coupler: Slightly larger at connection points
  • Lift rod: 5/16" fiberglass (passes through pipe)

4-Inch Casing Interior

  • Nominal ID: 4.026" (Schedule 40)
  • Actual space: Approximately 4" diameter

Compatibility Factors

Submersible Pump Size

The main variable is your submersible pump diameter:

Submersible SizeAvailable SpaceSimple Pump Fit
3" submersible~1.5"May be tight
4" submersibleMinimalUsually not compatible

Pitless Adapter Configuration

The pitless adapter can affect clearance:

  • Single-pipe pitless (most common)
  • Dual-port pitless (designed for backup pumps)
  • Position relative to Simple Pump drop pipe

Typical 4-Inch Well Scenario

What's Already in the Well

  1. Submersible pump at bottom
  2. Submersible discharge pipe (1" or 1.25")
  3. Electrical wiring/conduit
  4. Safety rope (if installed)
  5. Pitless adapter connection

Adding Simple Pump

  1. Simple Pump drop pipe (1" Schedule 80)
  2. Lift rod inside drop pipe
  3. Connection to pitless or well cap

Making It Work

Option 1: Verify Before Purchase

Contact us with:

  • Exact submersible pump model and diameter
  • Pitless adapter brand/model
  • Whether safety rope is present
  • Any other items in well

We can assess compatibility before you purchase.

Option 2: Pump Out of Well Cap

If pitless installation is too tight:

  • Install Simple Pump through well cap
  • Submersible uses pitless, Simple Pump uses cap
  • No conflict between systems
  • Manual carry of water (no pressure delivery)

Option 3: Dual-Port Pitless Adapter

Some pitless adapters accommodate two drop pipes:

  • Allows both pumps to connect
  • Both deliver to underground piping
  • Requires compatible adapter installation

Measurement Verification

Before attempting installation:

In-Well Measurement

  1. Remove well cap
  2. Shine flashlight into well
  3. Observe existing equipment position
  4. Measure available space if possible

Paper Test

Some customers lower a piece of paper tube (rolled to submersible size + 1.5") to verify clearance throughout well depth.

Our Recommendation

For 4-inch wells with existing submersibles:

Contact us before purchasing. Provide your submersible specifications and we'll assess compatibility. Many 4-inch well installations work fine, but verification prevents problems.

Alternative: 4-Inch to 6-Inch Casing Sleeve

If your well has a 4-inch liner inside a larger bored hole:

  • Well casing sleeve may allow access to larger diameter
  • Consult with well professional
  • Uncommon but worth checking

Need Compatibility Verification?

Send us your well details:

  • Casing diameter and material
  • Submersible pump make/model
  • Pitless adapter type
  • Well depth and water level

Technical Support: 877-492-8711 ext. 6

Need More Help?

Our technical support team is here to help with any questions about your Simple Pump system.