# Should a Sediment Filter Go Before or After a Well Pressure Tank?

Source: https://brictale.com/water/filtration/sediment-filter-before-or-after-well-pressure-tank
Published: 2026-08-25
Audience: Homeowner
Published by Brictale, a consumer home-intelligence publication. https://brictale.com

## Short answer

There is no universal side. A centrifugal separator designed for well sand may be manufacturer-specified between the pump and pressure tank, with the check valve before it and pressure switch after it. A cartridge housing may have a model-specific after-tank instruction; an automatic backwashing filter has no universal side because pressure, flow, drain, and regeneration requirements must match the exact system manual or qualified design. Map the existing check valve, switch, tank, and bypass before changing piping.

---

The right answer depends on what “sediment filter” means. A centrifugal sand separator designed for a residential well may belong between the pump and pressure tank when its manufacturer specifies that arrangement. A cartridge housing may be specified after the tank by its exact model manual. An automatic backwashing filter has no universal side: its restriction, bypass, drain, pressure, flow, and regeneration behavior must be matched to the exact system manual or a qualified design. The exact model manual controls.

That is not a contradiction. It is a device distinction. In LAKOS's residential separator instructions, the check valve is before the separator and the pressure switch is between the separator and the pressure tank. In Pentair's Pentek Dura-Series manual, the whole-house cartridge filter is installed after the water meter or pressure tank. Pentair's PC600-P/PC1000-P manual gives a similar after-tank caution for a well-water home, while separately describing the included sediment prefilter as a professional-installer decision that is typically “pre” for well applications. Read those as model-specific instructions, not a national rule that every filter belongs on one side.

## Classify the device before choosing the side

Start with the body, connections, and maintenance method—not with the word sediment on a sales page. The three categories below perform different jobs in a well system and create different installation constraints.

| Device you actually have | What it does | First placement question | Default decision posture |
|---|---|---|---|
| Centrifugal sand separator or spin-down separator with a purge leg | Separates heavier sand or sediment by a hydraulic process and discharges it through a purge valve | Does the exact manual put it between pump and pressure tank, and where does it put the check valve and pressure switch? | A pre-tank location can be manufacturer-supported. LAKOS's residential instructions are an example. |
| Cartridge housing with a replaceable pleated, spun, wound, or similar element | Traps particles until the element loads and creates pressure drop | Is the housing manual written for a well system, and does it specify after the pressure tank or meter? | Follow the exact housing manual; the cited Pentek Dura-Series is an after-tank example, not a rule for every housing. |
| Automatic backwashing filter with a control valve, media tank, and drain line | Uses a media bed and a programmed flow path to backwash or regenerate | Can the system supply the required service and backwash pressure and flow without disturbing pump control? | Do not assume either side; the exact system manual or qualified design must match pressure, flow, drain, and regeneration requirements. |

The labels can be misleading. A clear housing with a screen may be a washable strainer, a spin-down filter, or a simple cartridge prefilter. A tall tank with a motorized or metered valve may be sold as a “sediment filter” even though it needs a drain and a timed backwash. A small blue housing may be only the sediment stage of a larger carbon system. Photograph the label and model number before deciding.

### Why “before the tank” can be correct for a separator

The benefit of a pre-tank separator is protection at the point where well water enters the pressure-side equipment. LAKOS says its residential separators remove sand and sediment before they reach the pressure tank and household plumbing. Its installation page says to install the separator between the pump and pressure tank, put an above-ground check valve between the pump and separator, and route tees or diversions after the separator outlet. The accompanying SandMaster sheet repeats the order and places the pressure switch between the separator and pressure tank. ([LAKOS residential separator installation guide](https://www.lakos.com/residential-installation/); [LAKOS SandMaster installation instructions](https://www.lakos.com/wp-admin/admin-ajax.php?action=wpfd&juwpfisadmin=false&preview=1&task=file.download&token=&wpfd_category_id=261&wpfd_file_id=1721))

This is a narrow exception with conditions. LAKOS also specifies a minimum inlet pressure of 15 psi for the cited SandMaster sheet, requires operation within the model's recommended flow range, requires inlet and outlet pressure gauges for monitoring and troubleshooting, and says the separator must be purged regularly. The device is not a passive piece of pipe that can be placed anywhere for the same result. If a proposed pre-tank separator has no purge path, no model-specific flow range, or a manual that shows a different order, stop before copying the LAKOS diagram. ([LAKOS SandMaster installation instructions](https://www.lakos.com/wp-admin/admin-ajax.php?action=wpfd&juwpfisadmin=false&preview=1&task=file.download&token=&wpfd_category_id=261&wpfd_file_id=1721))

### Why a cartridge housing can start after the tank

A cartridge loads over time. The housing may have little pressure drop when new and materially more restriction when dirty, undersized, or fitted with a finer element. The cited Pentek Dura-Series manual says its whole-house filter must be installed after the water meter or pressure tank. It also says the cartridge has a limited service life and that a decrease in water flow indicates replacement is needed. That is a model-specific instruction, not a universal rule for every cartridge housing. ([Pentek Dura-Series Water Filter Installation and Operating Instructions](https://www.pentair.com/content/dam/extranet/nam/filtration/pentair/manuals/248332-dura-series-filter-man.pdf))

For a conventional pressure-tank well, the practical reason to begin downstream is control-path separation. The pump fills the tank; the pressure switch responds to system pressure at its sensing point; household demand is then supplied through the downstream piping. A cartridge restriction after the tank can reduce pressure at fixtures, but it does not need to sit between the pump discharge and the tank's pressure-sensing arrangement. That preserves a clearer distinction between a pump or tank problem and a dirty treatment element.

This is hydraulic reasoning, not a claim that every pressure switch is in the same place. Some systems have unusual piping, a constant-pressure controller, a booster pump, or a treatment package designed around a different sensing point. Use the manual and the actual pipe map. Do not relocate a switch, add a check valve, or remove a filter solely because a generic diagram makes the order look simpler.

### Why a backwashing filter needs more than a pipe arrow

An automatic backwashing filter is both treatment equipment and a flow-control event. Its valve may send water to a drain, pause flow, reverse flow through the media, or require a programmed minimum pressure. In the Fleck 5600 service manual, the regeneration valve requires at least 25 psi to operate effectively. Its troubleshooting table lists drain-flow control, a restricted drain line, and low water pressure under inadequate backwash flow; an incorrectly sized unit appears under a separate loss-of-pressure entry, so those causes should not be collapsed into one diagnosis. ([Fleck 5600 Service Manual](https://www.pentair.com/content/dam/extranet/web/nam/fleck/manuals/40106-fleck-5600-manual.pdf))

That is why “put the filter before the tank so the tank is protected” is incomplete advice for a backwashing unit. The filter must be sized and piped so its service pressure, backwash flow, drain line, bypass, and control logic work together. A pre-tank location may also put a restriction or a changing valve state in the water path that the pump-control system uses to fill the tank. The cited Fleck manual says system installation requires information from multiple suppliers and should be performed by a plumbing professional; it does not authorize a universal before-tank arrangement.

## Map the existing well flow without opening anything

Before judging an installation, build a visible flow map from the pump discharge toward the house. This is an observation task, not a pressure-vessel or electrical repair task. The goal is to answer four questions:

1. Where does water enter the building from the well or well equipment?
2. Where is the first check valve that you can identify from an external label or service record?
3. Where are the pressure tank and pressure switch relative to the filter?
4. Does the treatment device have a bypass, purge outlet, or drain connection?

### The safe observation procedure

Use a phone camera, flashlight, and paper sketch. Keep covers closed. From a dry standing position, photograph model and direction arrows on the pump-control equipment, tank tee, gauges, filter head, bypass, and backwash valve. Do not remove a pressure-switch cover to see wires. Do not unscrew a gauge, cartridge sump, purge cap, drain fitting, or tank connection to “confirm” flow direction.

Trace the pipe visually. Mark each branch with an arrow only when you can see the connection. A line that disappears through a wall is unknown; do not fill the gap with an assumption. Note any tee going to irrigation or an outbuilding. A tee before a separator may leave that branch unprotected; LAKOS specifically says diversions should be after its separator outlet for the cited residential application.

Record what the instrument faces show when no fixture is open and when one repeatable cold-water fixture is running. This does not require opening a control. Write down the gauge location, the pressure before demand, the pressure during demand, and whether the pump starts. Treat the readings as observations, not calibrated proof. If the gauge is damaged, stuck, fogged, or outside its scale, tell the professional rather than tapping it.

{{visual:safe-flow-path-verification}}

### What the components tell you—and what they do not

| Observation | Reasonable inference | Do not infer |
|---|---|---|
| A tall tank has a motorized valve and drain line | It may be an automatic backwashing or conditioning unit | That it can be moved before the pressure tank without checking backwash requirements |
| A clear sump has a removable element and pressure-relief button | It is likely a cartridge housing | That every replacement cartridge has the same flow, pressure, or service life |
| A separator has a purge outlet and collection chamber | It may be a centrifugal separator | That the purge valve can discharge safely or that the model supports your pump flow |
| Pressure drops only when water is flowing through treatment | A restriction may be downstream of the gauge or treatment may be loaded | That the pump, tank, or switch is healthy |
| Pressure switch is mounted near the tank tee | The switch likely senses pressure at that point | That another filter location is safe without checking the sensing connection and manual |
| A check valve is visible on the above-ground discharge line | There is at least one accessible check valve | That there is no additional check valve at the pump or elsewhere |

Penn State Extension describes the pressure tank as maintaining pressure in the pipeline and the pressure-activated switch as stopping and starting the pump at the system's operating points. ([Penn State Extension: Using Low-Yielding Wells](https://extension.psu.edu/using-low-yielding-wells)) That general description helps explain why the location of a restriction or check valve matters, but it does not identify the components in your particular system.

### Why the check valve matters

A check valve controls reverse flow when the pump stops. In the LAKOS arrangement, the manufacturer places the check valve between pump and separator, then puts the pressure switch on the separator's tank side. If your proposed separator is installed with the check valve on the wrong side, the pump may not see the intended hydraulic conditions and the separator may not match its manual's operating sequence.

Do not add a second check valve because a diagram seems to show one. Multiple check valves, a blocked sensing port, or a treatment valve that changes state can produce pressure behavior that looks like a bad tank or a failing pump. A licensed well or plumbing professional should verify the system design before altering control-path components.

## Compare the three installation paths

Use this decision surface after you have the model number and a sketch. “Yes” means the exact manual or an installer-designed system confirms the condition; “looks like it” is not enough.

| Decision point | Separator designed for pre-tank sand removal | Cartridge housing | Automatic backwashing filter |
|---|---|---|---|
| Does the manual explicitly show it before the tank? | If yes, pre-tank may be correct | Usually no; many specify after tank or meter | Not assumed |
| Where should the check valve and pressure switch be? | Follow the device diagram exactly; LAKOS places check valve before and switch after | Keep the pressure-tank control path intact unless manual says otherwise | Confirm control valve, tank, pump, and drain sequence with installer |
| What happens as the device loads? | Collection chamber accumulates sand; purge is required | Element restriction increases; flow may fall | Media or valve may reduce service flow and require backwash flow |
| What gauges help? | Inlet and outlet pressure gauges are required by the cited LAKOS sheet for monitoring and troubleshooting | Gauge locations on both sides help compare restriction if the design provides them | A professional may need service, drain, and pressure measurements |
| Is a bypass important? | Isolation and purge valves must match the separator manual | A bypass can preserve water during cartridge service, but it can also send untreated water to the home | Bypass must not defeat required backwash or leave the valve in the wrong mode |
| Safest default when the manual is missing | Pause and identify the model | Ask for model-specific after-tank confirmation | Have a qualified installer design the full flow and drain arrangement |

### The manufacturer-backed paths

**Path A: pump → check valve → separator → pressure switch/tank → home.** Choose this only when the separator manual supports the order and the purge, mounting, flow range, and gauge requirements can be met. For the cited LAKOS SandMaster sheet, the separator must be between pump and pressure tank, the check valve must be between pump and separator, and the pressure switch must be between separator and tank. The sheet also calls for a near-upright installation and independent support. Those details are part of the decision, not optional illustration labels.

**Path B: pump → pressure tank/switch → cartridge housing → home.** This is the starting point for a conventional whole-house cartridge installation when the model manual specifies after the tank. Provide a service shutoff and a manufacturer-compatible bypass if the design calls for one. The housing must be accessible for service with clearance below it; the Dura-Series manual, for example, specifies clearance for cartridge changes and warns against pressurized or leaking conditions during service. Cartridge size, micron rating, maximum pressure, and flow must be taken from the exact housing and element documentation.

**One possible designed path: pump → pressure tank/switch → backwashing filter → home, with a designed drain and bypass.** Treat this as a system design, not a universal placement rule or simple filter swap. Confirm service flow, backwash flow, drain size and routing, minimum pressure, control power, freeze protection, and what happens if the unit is in bypass or loses power. The Fleck 5600 manual documents a minimum pressure for effective regeneration and provides specific backwash and drain-flow troubleshooting; it does not establish that every automatic backwashing filter belongs after the tank. Another valve or media tank may have different requirements.

### The ambiguous path: a prefilter included with a treatment package

Pentair's PC600-P/PC1000-P manual is useful because it shows why two statements can both appear in a manufacturer's literature. The manual cautions that the system itself should follow the pressure tank in a well-water home. Elsewhere, it says the included sediment prefilter's location is at the discretion of the professional installer and gives a typical pre position for well-water applications. That means “prefilter before the carbon tank” is not automatically the same as “prefilter before the well pressure tank.” ([Pentair PC600-P/PC1000-P Whole House Water Filter System Installation and Owner's Manual](https://www.pentair.com/content/dam/extranet/nam/filtration/pentair/manuals/4006016-pc600-p-pc1000-p-system-manual.pdf))

Read the diagram's incoming-water label carefully. Is “pre” referring to before the carbon media tank, or before the well pressure tank? Those are different reference points. If the manual does not draw the well pump, check valve, pressure switch, and pressure tank, do not extend the diagram beyond its stated scope.

## Read pressure, flow, and maintenance signals

The most useful homeowner evidence is a before-and-after record made under the same demand. Do not use it to adjust the switch or tank. Use it to tell a professional whether the filter order, filter condition, or pump-control behavior deserves investigation.

### A repeatable observation

Choose one cold-water fixture with a stable, ordinary flow. With discretionary water use stopped, record:

- Date and time.
- Which fixture was used and whether other fixtures, irrigation, or treatment cycles were off.
- Gauge location and pressure before opening the fixture.
- Pressure while the fixture runs.
- Whether the pump starts, stops, or runs continuously.
- Whether flow starts strong and fades.
- Whether the symptom changes when the treatment bypass is used by its normal labeled handle position—only if the bypass can be operated without opening equipment and the manufacturer permits homeowner operation.

Do not interpret one low reading as proof of a clogged filter. A restriction can be in the cartridge, a partly closed valve, a blocked screen, a frozen or damaged section, the main line, or the well/pump system. A pump may also fail to deliver its expected flow. Compare the location of the gauge with the location of the treatment device: a gauge upstream can remain steady while a downstream fixture loses pressure.

### What the symptom supports

| Pattern you can observe | What it supports | Next safe step |
|---|---|---|
| Flow is good after service and fades as days pass | Loading or maintenance demand may be involved | Record service date, element model, and pressure/flow trend; have restriction measured across the device |
| Pump cycles rapidly after a new filter is installed | Added restriction, changed valve position, leak, or control issue may be involved | Stop repeated testing and provide the original and new pipe map to a professional |
| Pressure is low only at fixtures after the tank | A downstream restriction is possible | Check only visible valve handles and labels; do not open a pressurized housing; arrange inlet/outlet measurement |
| Backwashing fails or drain flow is weak | The control valve, power, drain, pressure, flow control, or media may be involved | Do not manually force the valve through a cycle; use the model manual and service professional |
| Sand reaches the tank or house despite a separator | Flow range, purge, installation order, or source condition may be wrong | Record purge history and visible sediment; have the separator and well system evaluated |
| Pressure switch chatters or the pump starts when no water is used | Tank, sensing connection, check valve, leak, or control fault may be involved | Stop at observation; never open the switch cover or adjust controls as a placement test |

### Maintenance consequences are part of placement

A pre-tank separator can protect the pressure tank only if its collection chamber is purged on the interval and method specified for that model. The cited LAKOS SandMaster sheet recommends at least weekly manual purging and gives more frequent automatic intervals for heavier sand loads; it also warns against letting separated sand compact in the chamber. That is not a universal interval for every separator. Use the label and manual for your model.

A cartridge housing needs an element-change plan based on the model, element, water quality, and observed restriction. The Pentek Dura-Series manual lists model-specific flow and pressure-drop information for its replacement cartridges and states that a decrease in water flow indicates replacement. Do not select a fine micron element by marketing label alone if the pump and home demand cannot support its pressure drop.

A backwashing filter needs a reliable drain, the correct flow control, enough pressure and flow, a working timer or controller, and a schedule matched to the water and media. The Fleck troubleshooting table lists a restricted drain, a clogged flow control, and low water pressure under inadequate backwash flow. It places an incorrectly sized unit under a separate loss-of-pressure entry, not in that backwash-flow cause list. A unit that “filters” in service but cannot backwash is not operating as designed; leaving it in that condition can create pressure loss or media problems. ([Fleck 5600 Service Manual](https://www.pentair.com/content/dam/extranet/web/nam/fleck/manuals/40106-fleck-5600-manual.pdf))

## Make the change decision and hand off scope

Use this three-part test before approving a piping change.

### 1. The exact manual supports the order

Save the current manual as a PDF or print the relevant diagram. Highlight the words that identify the reference point: pump, pressure tank, check valve, pressure switch, meter, treatment tank, or house. If the manual says “pre-filter” but does not say pre-pressure-tank, keep the scope limited to the treatment package until a qualified installer confirms the well-system order.

For a LAKOS-style separator, confirm the model flow range, required inlet pressure, purge arrangement, gauges, orientation, support, and check-valve/switch positions. For a cartridge, confirm pressure rating, flow, element compatibility, service clearance, and after-tank direction. For a backwashing unit, confirm service flow, backwash flow, drain requirements, minimum pressure, bypass, power, and freeze limits.

### 2. The existing system map does not put a restriction in an unexplained control path

The pressure tank should remain close to its pressure switch where the tank manufacturer requires that arrangement. Amtrol says proximity reduces added friction loss and pressure-switch bouncing. Its manual also warns that well tanks are pressure vessels and that precharge work should be performed only by qualified professionals under the specified conditions. ([Amtrol Pre-Charged Well Tanks Installation and Operation Instructions](https://www.amtrol.com/wp-content/uploads/2019/07/9015-939-04_18-Precharged-Well-Tanks-IO.pdf))

That does not mean every downstream filter is harmless or every pre-tank device is unsafe. It means the proposed change should identify what the switch senses, where the check valve sits, what the tank sees during demand, and whether a restriction or regeneration cycle can starve or isolate the control point. If those answers are not on paper, the correct next step is a professional design check—not a test relocation.

### 3. The change has a measurable acceptance test

Before work, define what will be recorded: pump start and stop pressures, pressure at a stated flow, inlet/outlet differential across the treatment device, backwash drain flow where applicable, purge result for a separator, and whether pressure holds with normal household demand off. After work, repeat the same observations. A pressure number without a flow condition is incomplete evidence.

Ask the installer to note:

- The final flow direction and location of the check valve, pressure switch, tank, gauges, isolation valves, bypass, purge, and drain.
- The exact model and element or media installed.
- Any pressure or flow limit used for sizing.
- The normal cartridge, purge, or backwash maintenance interval.
- What untreated water flows through in bypass.
- What symptom should trigger service and what reading would be considered abnormal.

Do not accept “before the tank protects the tank” or “after the tank is always correct” as a complete explanation. Ask which device manual supports the order and which measurement will show that the system still controls the pump and delivers the intended flow.

## Safety boundary and homeowner record

This decision surface is for classification, observation, and scope definition. It is not permission to open or modify pressurized or energized equipment.

Placement, pressure readings, and backwash compatibility do not establish microbiological safety or disinfection. Do not treat unknown or microbiologically unsafe well water as potable based on this page. The [Fleck 5600 service manual](https://www.pentair.com/content/dam/extranet/web/nam/fleck/manuals/40106-fleck-5600-manual.pdf) limits the system to potable-quality water and says water that is microbiologically unsafe or of unknown quality needs adequate disinfection before and after the system. Test the well water as appropriate and obtain qualified treatment and disinfection review before relying on it for drinking, cooking, or other potable uses.

Plumbing, electrical, well-work, licensing, permit, and code requirements vary by jurisdiction. The cited Fleck manual says its installation must comply with state and municipal plumbing and electrical codes, notes that permits may be required, and says system installation should be performed by a plumbing professional. Before changing the flow path, verify current requirements with the local building, health, or water authority and an appropriately qualified well, plumbing, and electrical professional.

Do not open a pressure-switch or pump-control cover, test live wiring, bypass an electrical safety, pull a pump, open the well, enter a well pit or other confined space, loosen a tank tee, remove a pressurized cartridge sump, open a purge or drain fitting under pressure, or adjust tank precharge or pressure-switch settings as a placement experiment. Do not manipulate a corroded tank, leaking relief valve, bulged housing, or damaged pipe. Assign those tasks to a qualified well, plumbing, or electrical professional as appropriate.

Pentair's whole-house manual warns about electrical grounding continuity when its system is installed in conductive plumbing and directs homeowners to consult a qualified electrician for questions about the home's electrical system. Amtrol warns that pressure-vessel damage and incorrect precharge work can cause rupture, injury, flooding, or property damage. Those warnings are why a photo-and-record inspection is the useful homeowner boundary.

### Stop and escalate when you see

- A tank, housing, fitting, or pipe that leaks, bulges, splits, or shows serious corrosion.
- Sparking, a hot smell, wet wiring, an open electrical cover, or a repeatedly tripping breaker.
- Uncontrolled pressure, a relief valve discharging, or a gauge beyond the equipment rating.
- A pump that runs without building pressure, runs dry, or cycles repeatedly with all visible demand off.
- A backwashing filter that cannot complete its cycle, has no safe drain, or sends media to fixtures.
- Sudden sand, cloudy water, air, odor, or a water-quality change that could indicate a well or source problem.

Bring the professional the model photos, the manual links, the pipe sketch, the gauge locations, the observed symptom, the date of the last cartridge change or purge, and the controlled before/after notes. The best answer to “before or after?” is not a universal arrow. It is a documented match between the device's manual, the actual check-valve and pressure-switch arrangement, the required maintenance path, and a safe acceptance test.

## Evidence

- [Residential Separator Installation Guide](https://www.lakos.com/residential-installation/) — LAKOS residential separators; this is a manufacturer-specific installation instruction, not a rule for every sediment device.
- [SandMaster Series Installation & Operating Instructions](https://www.lakos.com/wp-admin/admin-ajax.php?action=wpfd&juwpfisadmin=false&preview=1&task=file.download&token=&wpfd_category_id=261&wpfd_file_id=1721) — The cited SandMaster residential instruction sheet; the differential and purge intervals apply to that product family and its stated operating conditions.
- [Pentek Dura-Series Water Filter Installation and Operating Instructions](https://www.pentair.com/content/dam/extranet/nam/filtration/pentair/manuals/248332-dura-series-filter-man.pdf) — Pentek Dura-Series cartridge housing and listed replacement cartridges; do not generalize its placement or service limits to another housing without that model's manual.
- [PC600-P | PC1000-P Whole House Water Filter System Installation and Owner's Manual](https://www.pentair.com/content/dam/extranet/nam/filtration/pentair/manuals/4006016-pc600-p-pc1000-p-system-manual.pdf) — Pentair's specified PC600-P/PC1000-P system and its included sediment prefilter; the manual itself reserves final placement to a professional installer.
- [Fleck 5600 Service Manual](https://www.pentair.com/content/dam/extranet/web/nam/fleck/manuals/40106-fleck-5600-manual.pdf) — Fleck 5600 filter/softener control valve and its documented installation and troubleshooting conditions; exact media, flow control, and model requirements vary.
- [Fleck 5600 Service Manual](https://www.pentair.com/content/dam/extranet/web/nam/fleck/manuals/40106-fleck-5600-manual.pdf) — The cited Fleck 5600 manual's product-safety boundary; this does not establish that a homeowner's well water is potable or that any other treatment device disinfects water.
- [Fleck 5600 Service Manual](https://www.pentair.com/content/dam/extranet/web/nam/fleck/manuals/40106-fleck-5600-manual.pdf) — The cited Fleck 5600 installation boundary; local well-work, licensing, permit, plumbing, and electrical requirements must be checked with the applicable authority and qualified professionals.
- [Pre-Charged Well Tanks Installation and Operation Instructions](https://www.amtrol.com/wp-content/uploads/2019/07/9015-939-04_18-Precharged-Well-Tanks-IO.pdf) — Amtrol pre-charged well tanks and the cited safety instructions; this supports the control-path reasoning and safety boundary, not a universal pipe-order code.
- [Using Low-Yielding Wells](https://extension.psu.edu/using-low-yielding-wells) — General private-well system function described by Penn State Extension; example pressures in the source are illustrative, not a homeowner's assumed settings.