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Grundfos 4 in SP Submersible Well Pumps
Grundfos 77S SP Submersible Well Pump
Grundfos
Grundfos 77S SP Submersible Well Pump
- Price
- From $3,820
Grundfos 62S SP Submersible Well Pump
Grundfos
Grundfos 62S SP Submersible Well Pump
- Price
- From $3,338.67
Grundfos 45S SP Submersible Well Pump
Grundfos
Grundfos 45S SP Submersible Well Pump
- Price
- From $3,412
Grundfos 35S SP Submersible Well Pump
Grundfos
Grundfos 35S SP Submersible Well Pump
- Price
- From $2,869.33
Grundfos 25S SP Submersible Well Pump
Grundfos
Grundfos 25S SP Submersible Well Pump
- Price
- From $2,544
Grundfos 16S SP Submersible Well Pump
Grundfos
Grundfos 16S SP Submersible Well Pump
- Price
- From $2,317.33
Grundfos 10S SP Submersible Well Pump
Grundfos
Grundfos 10S SP Submersible Well Pump
- Price
- From $2,164
Grundfos 7S SP Submersible Well Pump
Grundfos
Grundfos 7S SP Submersible Well Pump
- Price
- From $2,513.33
Grundfos 5S SP Submersible Well Pump
Grundfos
Grundfos 5S SP Submersible Well Pump
- Price
- From $2,725.33
Grundfos 4 in SP Submersible Well Pumps
Grundfos 4 in SP
Stainless Steel Submersible Well Pumps
The Grundfos SP range in 100 percent AISI 304 stainless steel, for drilled wells from a single-family home to high-flow agriculture. Nine flow families from 5 to 77 GPM, 1/2 to 20 HP, complete with a matched motor and control box. Call 1-888.510.4036 and we will size one for your well.
9Flow families
5–77 GPMRated flow
1/2–20 HPMotor range
to 1,600 ftNominal head
NSF 61 / 372Pump-end listing
Grundfos builds the SP submersible range in 100 percent stainless steel for long life, sand resistance and resistance to aggressive water. Every complete pump ships as a stainless pump end matched to a Grundfos submersible motor — and, on 3-wire single-phase units, the matching control box.
We supply these pumps in their U.S. 60 Hz configuration with NPT connections, and will size one for your well against pumping water level, delivery pressure and piping losses. Compare the flow families below, or call 1-888.510.4036. Genuine Grundfos equipment, factory-new in original packaging — sold and supported by Watermain Supply, an independent industrial supplier.
The SP Flow Families
Nine families from 5 to 77 GPM. Pick the family that matches your peak demand, then the model whose head clears your well.
5S SP
5 GPM stainless submersible
5 GPMRated flow
184–909 ftNominal head
1/2–3 HPMotor
1 in NPTDischarge
A nominal 5 GPM 4 in stainless steel submersible pump family for drilled wells, in 24 complete-pump configurations. 100 percent AISI 304 stainless, 2-wire or 3-wire single-phase and three-phase motor options, matched motor and control box in the box.
Best forDomestic and light-commercial well supply, irrigation and pressure boosting where 5 GPM-class flow meets the demand.
View 5S SP pumps
7S SP
7 GPM stainless submersible
7 GPMRated flow
164–630 ftNominal head
1/2–2 HPMotor
1 in NPTDischarge
A nominal 7 GPM 4 in stainless steel submersible pump family for drilled wells, in 17 complete-pump configurations. 100 percent AISI 304 stainless, 2-wire or 3-wire single-phase and three-phase motor options, matched motor and control box in the box.
Best forDomestic and light-commercial well supply, irrigation and pressure boosting where 7 GPM-class flow meets the demand.
View 7S SP pumps
10S SP
10 GPM stainless submersible
10 GPMRated flow
126–1225 ftNominal head
1/2–5 HPMotor
1-1/4 in NPTDischarge
A nominal 10 GPM 4 in stainless steel submersible pump family for drilled wells, in 26 complete-pump configurations. 100 percent AISI 304 stainless, 2-wire or 3-wire single-phase and three-phase motor options, matched motor and control box in the box.
Best forDomestic and light-commercial well supply, irrigation and pressure boosting where 10 GPM-class flow meets the demand.
View 10S SP pumps
16S SP
16 GPM stainless submersible
16 GPMRated flow
112–1636 ftNominal head
1/2–10 HPMotor
1-1/4 in NPTDischarge
A nominal 16 GPM 4 in stainless steel submersible pump family for drilled wells, in 24 complete-pump configurations. 100 percent AISI 304 stainless, 2-wire or 3-wire single-phase and three-phase motor options, matched motor and control box in the box.
Best forDomestic and light-commercial well supply, irrigation and pressure boosting where 16 GPM-class flow meets the demand.
View 16S SP pumps
25S SP
25 GPM stainless submersible
25 GPMRated flow
64–1082 ftNominal head
1/2–10 HPMotor
1-1/2 in NPTDischarge
A nominal 25 GPM 4 in stainless steel submersible pump family for drilled wells, in 24 complete-pump configurations. 100 percent AISI 304 stainless, 2-wire or 3-wire single-phase and three-phase motor options, matched motor and control box in the box.
Best forDomestic and light-commercial well supply, irrigation and pressure boosting where 25 GPM-class flow meets the demand.
View 25S SP pumps
35S SP
35 GPM stainless submersible
35 GPMRated flow
61–1482 ftNominal head
3/4–20 HPMotor
1-1/2 in NPTDischarge
A nominal 35 GPM 4 in stainless steel submersible pump family for drilled wells, in 60 complete-pump configurations. 100 percent AISI 304 stainless, 2-wire or 3-wire single-phase and three-phase motor options, matched motor and control box in the box.
Best forDomestic and light-commercial well supply, irrigation and pressure boosting where 35 GPM-class flow meets the demand.
View 35S SP pumps
45S SP
45 GPM stainless submersible
45 GPMRated flow
72–942 ftNominal head
1–15 HPMotor
2 in NPTDischarge
A nominal 45 GPM 4 in stainless steel submersible pump family for drilled wells, in 40 complete-pump configurations. 100 percent AISI 304 stainless, 2-wire or 3-wire single-phase and three-phase motor options, matched motor and control box in the box.
Best forDomestic and light-commercial well supply, irrigation and pressure boosting where 45 GPM-class flow meets the demand.
View 45S SP pumps
62S SP
62 GPM stainless submersible
62 GPMRated flow
40–486 ftNominal head
3/4–10 HPMotor
2 in NPTDischarge
A nominal 62 GPM 4 in stainless steel submersible pump family for drilled wells, in 38 complete-pump configurations. 100 percent AISI 304 stainless, 2-wire or 3-wire single-phase and three-phase motor options, matched motor and control box in the box.
Best forDomestic and light-commercial well supply, irrigation and pressure boosting where 62 GPM-class flow meets the demand.
View 62S SP pumps
77S SP
77 GPM stainless submersible
77 GPMRated flow
37–396 ftNominal head
3/4–10 HPMotor
2 in NPTDischarge
A nominal 77 GPM 4 in stainless steel submersible pump family for drilled wells, in 32 complete-pump configurations. 100 percent AISI 304 stainless, 2-wire or 3-wire single-phase and three-phase motor options, matched motor and control box in the box.
Best forDomestic and light-commercial well supply, irrigation and pressure boosting where 77 GPM-class flow meets the demand.
View 77S SP pumps
Comparing The Flow Families
The flow family is the first decision; the model within it sets how deep a well it holds that flow in.
| Family | Rated flow | Nominal head span | Motor | Discharge | Configurations |
|---|---|---|---|---|---|
| 5S SP | 5 GPM | 184–909 ft | 1/2–3 HP | 1 in NPT | 24 |
| 7S SP | 7 GPM | 164–630 ft | 1/2–2 HP | 1 in NPT | 17 |
| 10S SP | 10 GPM | 126–1225 ft | 1/2–5 HP | 1-1/4 in NPT | 26 |
| 16S SP | 16 GPM | 112–1636 ft | 1/2–10 HP | 1-1/4 in NPT | 24 |
| 25S SP | 25 GPM | 64–1082 ft | 1/2–10 HP | 1-1/2 in NPT | 24 |
| 35S SP | 35 GPM | 61–1482 ft | 3/4–20 HP | 1-1/2 in NPT | 60 |
| 45S SP | 45 GPM | 72–942 ft | 1–15 HP | 2 in NPT | 40 |
| 62S SP | 62 GPM | 40–486 ft | 3/4–10 HP | 2 in NPT | 38 |
| 77S SP | 77 GPM | 37–396 ft | 3/4–10 HP | 2 in NPT | 32 |
Quick rule. Choose the flow family for your peak demand at design pressure, not the maximum flow on the label. Then step up a model if your duty point lands past 70 percent of that model’s maximum head.
Rated Performance
Documented duty points from the Grundfos SP easy-selection charts, U.S. 60 Hz. Gallons per minute at 40 psi and 200 ft to pumping water level.
| Model | Motor | 40 psi at 200 ft | Max shut-off |
|---|---|---|---|
| 10S15-21 | 1-1/2 HP | 12.2 GPM | 237 psi |
| 10S30-27 | 3 HP | 13.5 GPM | 285 psi |
| 16S15-14 | 1-1/2 HP | 15.0 GPM | 167 psi |
| 16S20-18 | 2 HP | 18.5 GPM | 194 psi |
| 25S20-11 | 2 HP | 11.4 GPM | 135 psi |
| 25S30-15 | 3 HP | 26.0 GPM | 170 psi |
Boost in psi equals head in feet multiplied by 0.433. Full per-model tables are on each product page. Grundfos publishes easy-selection charts for the 5S through 25S families; the 35S and larger families are sized from the pump curve. Figures are approximate — confirm against the current Grundfos SP data booklet before specifying.
Sizing & Best Practices
How we size an SP pump, and what to check before installing.
1. Calculate the total head
Total head = depth to pumping water level at your maximum draw + the pressure you want in feet (psi × 2.31) + above-grade lift + friction loss in the drop pipe and discharge line. Size the pump so its head at your flow clears that number.
2. Estimate peak flow honestly
Use WSFU / Hunter’s curve (IPC Table 604.3) for residential demand and the IAPMO Water Demand Calculator for light commercial. A single-family home usually peaks at 8–12 GPM — match that to the 5S, 7S or 10S family rather than the flow on the label.
3. Choose 2-wire or 3-wire
2-wire single-phase needs no control box and is the simplest install. 3-wire single-phase uses a surface control box (included) and covers more horsepower. Three-phase needs a starter or a CUE drive and is the choice for the largest motors.
4. Check the well and the limits
Minimum well casing or sleeve is 4 in. Set the motor at least a few feet below maximum drawdown, above the well screen and clear of the bottom. Liquid temperature above 86 °F requires flow past the motor, which usually means a flow sleeve.
Sizing rule of thumb. If your duty point lands past 70 percent of a model’s maximum head at design flow, step up a model. It runs cooler, quieter and closer to its best efficiency.
Which SP Pump Do You Need?
Selection by application; call with your well depth, fixture count and required flow for an engineering-led pick.
| Application | Typical demand | Recommended | Notes |
|---|---|---|---|
| Single-family home | 8–12 GPM at 50 psi | 5S, 7S or 10S, 1/2–1 HP | Match head to well depth plus pressure |
| Larger home, constant demand | 12–25 GPM | 10S, 16S or 25S | Higher flow family; size head to depth |
| Light commercial or irrigation | 25–45 GPM | 25S, 35S or 45S | Step up a family if peak demand is sustained |
| High-flow ag or municipal | 45–77 GPM | 45S, 62S or 77S | Lower head per family; confirm against the curve |
| Deep well, moderate flow | 5–16 GPM, 600–1200 ft | 5S, 10S or 16S at higher HP | The tall-head models reach the deepest settings |
What Makes A Grundfos SP Different
Why the SP range is the reference for stainless submersibles.
100 percent stainless
Pump end, sleeve, shaft and motor housing in AISI 304 throughout, inside and outside. Sand resistant, resistant to aggressive water, and light enough to handle and service easily.
Bearings with sand channels
Water-lubricated, squared bearings let sand particles leave the pump with the pumped liquid rather than grinding inside it.
Priming screw
Every 4 in radial-impeller pump carries a priming screw that keeps the pump bearings lubricated, preventing dry running.
Spring-assisted check valve
A built-in check valve with a short closing time keeps water hammer to a minimum, in a casing shaped to minimise pressure loss.
Motor and control box matched
The complete pump arrives as a pump end matched to a Grundfos submersible motor, with the correct control box on 3-wire single-phase units. No mismatched sourcing.
2-wire or 3-wire, single or three phase
Every family offers the wiring and phase that suits the install — simple 2-wire, serviceable 3-wire, or three-phase for the biggest motors.
NSF 61 and 372 certified
The pump end is certified to NSF/ANSI 61 and NSF/ANSI 372 for potable water (MH26400), and the MS4000C motor holds IAPMO File 6591.
Constant-pressure ready
Pair a three-phase SP with a CUE or CUE 100 drive to hold a constant pressure across changing demand.
Grundfos SP vs A.Y. McDonald
We sell both lines. Here is the honest head-to-head at matched flow families, all-stainless build against all-stainless build, so you can choose on the merits.
10 GPM — Grundfos 10S vs A.Y. McDonald 24000 K
| Spec | Grundfos 10S SP | A.Y. McDonald 24000 K |
|---|---|---|
| Rated flow | 10 GPM | 10 GPM |
| Motor range | 1/2–5 HP | 1/2–5 HP |
| Pump-end material | 100% AISI 304 stainless throughout | Stainless pump end, shaft and coupling |
| Discharge | 1-1/4 in NPT | 1-1/4 in NPT |
| Wiring options | 2-wire, 3-wire 1Ph, 3Ph | 2-wire, 3-wire 1Ph, 3-wire 3Ph |
| Complete package | Pump end + motor (+ control box on 3-wire 1Ph) | Pump end + motor + leads; control box on 3-wire 1Ph, starter kit on 3Ph |
| Potable-water listing | NSF/ANSI 61 and 372 (MH26400) | Confirm listing on the model |
Verdict. Even at 10 GPM the two are close on paper. The Grundfos 10S carries the documented NSF 61 and 372 listing and the fully stainless build with sand-channel bearings and priming screw; the A.Y. McDonald 24000 ships with the motor starter kit included on three-phase and is typically the lower-cost complete package. If first cost drives the job, the A.Y. McDonald wins; if the specification calls out NSF listing and long service life in sandy or aggressive water, the Grundfos does.
15 GPM — Grundfos 16S vs A.Y. McDonald 24000 L
| Spec | Grundfos 16S SP | A.Y. McDonald 24000 L |
|---|---|---|
| Rated flow | 16 GPM | 15 GPM |
| Motor range | 1/2–10 HP | 1/2–5 HP |
| Nominal head span | 112–1636 ft | To roughly 5 HP head |
| Pump-end material | 100% AISI 304 stainless | Stainless pump end |
| Discharge | 1-1/4 in NPT | 1-1/4 in NPT |
Verdict. The Grundfos 16S rates a nominal 16 GPM against the A.Y. McDonald 15 GPM and reaches 10 HP and far deeper settings, so on a deep or high-head 15 GPM well the 16S has real headroom the 24000 L does not. For a shallow-to-moderate 15 GPM domestic well the A.Y. McDonald covers the duty at lower cost.
25 GPM — Grundfos 25S vs A.Y. McDonald 24000 M
| Spec | Grundfos 25S SP | A.Y. McDonald 24000 M |
|---|---|---|
| Rated flow | 25 GPM | 25 GPM |
| Motor range | 1/2–10 HP | 1–5 HP |
| Nominal head span | 64–1082 ft | To roughly 5 HP head |
| Discharge | 1-1/2 in NPT | 1-1/4 in NPT |
| Constant-pressure option | CUE / CUE 100 drive, factory package | Third-party drive |
Verdict. At 25 GPM the Grundfos 25S pulls ahead on head and horsepower and offers a factory constant-pressure package (CUE 100) the A.Y. McDonald line does not match. The A.Y. McDonald 24000 M remains the value pick for a straightforward fixed-speed 25 GPM well within its head range.
35 GPM — Grundfos 35S vs A.Y. McDonald 24000 R
| Spec | Grundfos 35S SP | A.Y. McDonald 24000 R |
|---|---|---|
| Rated flow | 35 GPM | 35 GPM |
| Motor range | 3/4–20 HP | 1–10 HP |
| Nominal head span | 61–1482 ft | To roughly 10 HP head |
| Configurations | 60 | 18 |
Verdict. On high-flow, high-head duty the Grundfos 35S reaches 20 HP and holds a far wider range of duty points; the A.Y. McDonald 24000 R covers the mainstream 35 GPM band at lower cost. A.Y. McDonald also offers the AutoPAC pre-assembled system (pump, motor, tank and control), which has no direct Grundfos equivalent in this range.
Where A.Y. McDonald wins. Lower first cost on most matched duties; a no-lead brass option (21000 series) and thermoplastic option (22000/25000) for buyers who do not need full stainless; the AutoPAC complete-system package; and three-phase units that ship with the starter kit included. We stock and support both — tell us the well and the budget and we will quote the honest fit.
Why Source Grundfos SP Pumps from Watermain Supply
The Right US Build
We supply the U.S. 60 Hz configuration with NPT connections and the correct 2-wire, 3-wire or three-phase motor — the build that drops into a North American well.
Complete, Matched Pumps
Pump end, motor and control box matched at the factory, so nothing arrives mismatched.
Engineering-Led Sizing
Send your well depth, pumping water level and required flow and we return a sized selection against the pump curve.
Multi-Brand Perspective
If an SP is not the right fit, we will say so and quote the one that is.
Account Terms Available
Net-30 for qualified contractor, property-management and municipal accounts.
Houston, Gulf Coast Service
Based in Houston and serving the Gulf Coast, with parts and aftermarket support for the SP range.
Accessories & Controls
Complete the installation with the matched Grundfos controls, drives and service parts. See the full range on the Grundfos Submersible Accessories collection.
SA-SPM6 Control Box
The starting control a 3-wire single-phase SP motor needs, matched by HP and voltage. Standard and Deluxe, 1/2 to 15 HP.
MP 204 Motor Protector
Electronic overload, dry-run, voltage, phase and temperature protection with a fault log. Protects motors up through 75 HP.
CUE & CUE 100 Drives
Variable-frequency drives that hold constant pressure across changing demand. The CUE 100 runs a three-phase SP motor from single-phase service.
Motor Leads & Kits
Replacement motor leads for MS402, MS4000 and MS6000C motors, and the nut and bolt kits that couple the pump end to its motor.
Genuine Grundfos parts, factory-new in original packaging. Tell us the pump model, motor nameplate and supply voltage and we will match the exact part.
Frequently Asked Questions
The questions we hear most on stainless submersible well pumps.
What is the difference between 2-wire and 3-wire?
A 2-wire motor has the starting components built into the motor and needs no control box — just power and a pressure switch. A 3-wire motor uses a separate control box that houses the start capacitor and relay. 2-wire is simpler to install; 3-wire is serviceable at the surface and available in more horsepower ratings. Every 3-wire single-phase complete pump here includes the matching control box.
Do I need a control box?
Only for 3-wire single-phase motors, and it is included with those complete pumps. 2-wire single-phase motors and three-phase motors do not use a control box.
How do I choose a flow family?
Pick the family whose rated flow matches your peak demand at design pressure — not the maximum flow on the label. Then choose the model within it whose head clears your pumping water level plus the pressure you want. A typical single-family home peaks around 8–12 GPM, which is 5S to 10S territory.
What size well casing do these fit?
The 4 in motor and pump fit a 4 in minimum well casing or sleeve. A few high-flow DS models are built into a stainless sleeve with a 6 in motor; those are noted on the product page.
Are these certified for potable water?
The SP pump end is certified to NSF/ANSI 61 and NSF/ANSI 372 (MH26400). The MS4000C motor holds IAPMO File 6591.
What does the model number mean?
In 25S30-15: 25 is the nominal flow family in GPM, S is the AISI 304 stainless range, 30 is motor horsepower times ten, and 15 is the number of impeller stages.
Can I run one on a constant-pressure drive?
Yes. Pair a three-phase SP with a CUE or CUE 100 drive for constant pressure. We also sell the 4 in CUE 100 packages, which arrive as a matched pump end, motor and drive under one order number.
What is not included?
Drop pipe, drop cable, wellhead fittings, a pressure or diaphragm tank, and (for 3-wire three-phase) a magnetic starter. The complete pump is the pump end plus its matched motor, plus the control box on 3-wire single-phase units.
How deep can I set the pump?
Set from the drawdown level, with the motor at least a few feet below maximum drawdown, above the well screen and clear of the bottom. The tall-head models in each family reach the deepest settings — up to roughly 1,600 ft of nominal head on 16S.
Ready to Size Your Well Pump?
Send us your well depth, pumping water level, required flow and delivery pressure. We will respond with a sized selection, the accessories to complete it and lead time.
Technical data on this page is taken from Grundfos U.S. 60 Hz product literature and is subject to change by the manufacturer. Confirm against the current installation manual and pump curve before specifying.
Grundfos and SP are trademarks of Grundfos Holding A/S, used here for product identification only.
Watermain Supply is a DBA of E4 Industrial LLC, an independent industrial supplier based in Houston, Texas.
Grundfos and SP are trademarks of Grundfos Holding A/S, used here for product identification only.
Watermain Supply is a DBA of E4 Industrial LLC, an independent industrial supplier based in Houston, Texas.
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