SP Submersible Groundwater Pumps

Grundfos SP is the stainless-steel submersible pump used for wells, boreholes and groundwater across the widest duty span of any Grundfos range. ForeverPure lists 708 SP configurations, with motors from 1/2 to 255 HP in single- and three-phase.

How SP model numbers work

An SP model reads as flow – stages. In SP 5A-9 the 5 is the nominal flow in US gpm and the 9 is the number of stages. More stages means more head at the same flow, which is how you reach deeper settings without changing the pump diameter.

US-market models are also written in the imperial form — 10S05-9 is a 10 gpm, 1/2 HP, nine-stage pump. Both naming styles appear in this catalogue and refer to the same hardware.

Sizing an SP for a well

Well diameter decides the pump body. 4″ casings take the small frames; 6″ and 8″ casings take the larger flow classes.
Total dynamic head is pumping water level plus surface pressure plus friction loss — not well depth. Setting depth alone will oversize the pump.
Flow must sit inside the well's sustainable yield. A pump that outruns the aquifer will cycle and burn out.
Motor — Grundfos MS and MMS submersible motors pair with SP ends; voltage and phase must match the service available at the site.

Stainless throughout. SP pumps are built in AISI 304 or 316 stainless rather than cast iron, which is why they hold up in sand-bearing, aggressive and high-chloride groundwater where cast-iron pumps pit and fail early. For seawater intake or high-chloride wells, specify the 316 variant.

Typical applications

Domestic and agricultural wells — irrigation, livestock, private supply
Municipal groundwater — potable abstraction and distribution
Industrial process water — raw-water supply into treatment plant
Seawater intake and RO feed — beach wells and intake caissons
Dewatering and mine drainage

Common questions

How do I read an SP model number?

Flow class first, stage count second. SP 5A-9 is a nominal 5 gpm pump with nine stages. In the US imperial form, 10S05-9 is 10 gpm, 1/2 HP, nine stages.

What size SP pump do I need for my well?

Work from three numbers: required flow in gpm, total dynamic head in feet, and the casing diameter. Total dynamic head is the pumping water level plus any surface pressure plus friction losses — it is not the same as the depth of the well.

Do SP pumps include the motor?

Some listings are complete pumps with a Grundfos submersible motor fitted; others are bare pump ends for pairing with an existing motor. Each product page states which it is.

Can SP pumps handle sandy or aggressive water?

Better than most. The stainless construction tolerates abrasives and chlorides far longer than cast iron, though heavy sand still shortens life on any pump — a sand separator is worth fitting where yield allows.

What is the difference between SP and SPE?

SPE adds an integrated variable-speed motor for constant-pressure control. SP runs at fixed speed and is controlled externally if required.

ForeverPure Corporation is an authorized Grundfos distributor. Send us a duty point or an existing model number and we will confirm the right configuration before you order — contact us.