CR, CRI, CRN Vertical Multistage Pumps

Grundfos CR is the vertical multistage pump most industrial water systems are built around: a stack of impellers in a slim vertical column that produces high pressure from a small footprint. ForeverPure lists 6,011 CR-family configurations — frame sizes 1 through 255, 1 to 27 stages, and motors from 1/3 to 300 HP.

The family splits on two decisions: what the wetted parts are made of, and whether the pump runs at fixed or variable speed. Get those right and the rest is sizing.

CR, CRI or CRN — choosing the material

The three share hydraulics. They differ in what touches the water, and that is what decides service life:

Series	Wetted materials	Typical duty	We list
CR	Cast iron head and base, AISI 304 stainless chambers and impellers	Clean, non-aggressive water — boiler feed, HVAC, general pressure boosting	1,141
CRI	AISI 304 stainless throughout, including head and base	Potable water, food and beverage, light chemical, washdown environments	771
CRN	AISI 316 stainless throughout	Seawater and brackish RO, chlorides, aggressive chemicals, high-purity water	1,572

Reverse osmosis? Specify CRN. Chloride attacks 304 stainless, and RO concentrate is exactly where that shows up. The higher molybdenum content of 316 is the reason CRN is the standard high-pressure feed pump on SWRO and BWRO skids — including the systems ForeverPure builds.

Fixed speed or E-Pump

Add an E and the pump carries an integrated Grundfos MGE variable-frequency motor: CRE, CRIE and CRNE are the CR, CRI and CRN hydraulics with speed control built in, no external VFD, no panel space, no separate wiring.

Fixed speed (3,484 models) — lower purchase cost, ideal where flow is steady or a system controller already handles modulation.
E-Pump (2,527 models) — holds constant pressure as demand varies, soft-starts to protect membranes and piping, and cuts energy sharply on any load that spends time below full flow.

On variable-demand systems the E-Pump usually wins on total cost within a few years, because a throttled fixed-speed pump burns the difference across a valve. On a flat 24/7 duty, it rarely does.

Sizing: frame size and stage count

A CR model number reads frame – stages. In CR 15-7, the 15 is the nominal flow class in m³/h and the 7 is the number of impellers stacked in the column.

Frame size sets flow. Available here: 1, 1S, 3, 5, 10, 15, 20, 32, 45, 64, 95, 125, 155, 185, 215, 255.
Stage count sets pressure. More impellers, more head, same flow. This range runs 1 to 27 stages.

Pick the frame from the flow you need, then the stage count from the head. If two combinations reach the same duty point, the larger frame with fewer stages is generally the shorter, cheaper and more efficient pump.

Typical applications

Reverse osmosis — high-pressure membrane feed on SWRO and BWRO systems (CRN)
Boiler feed and condensate — high head, hot water, continuous duty
Pressure boosting — commercial buildings, irrigation, process supply
Filtration and industrial process — cooling loops, washdown, CIP circuits
Chemical transfer — where 316 stainless is required for compatibility

Common questions

What is the difference between CR, CRI and CRN?

Identical hydraulics, different wetted materials. CR uses a cast iron head and base with 304 stainless internals; CRI is 304 stainless throughout; CRN is 316 stainless throughout. Choose by water chemistry — CRN for chlorides, seawater and RO.

What does the E in CRE, CRIE and CRNE mean?

An integrated variable-speed MGE motor. The pump maintains a pressure setpoint by varying its own speed, so no external VFD is required.

How do I read a model number like CR 5-7?

The first figure is the nominal flow class in m³/h; the second is the number of stages. CR 5-7 is a 5 m³/h frame with seven impellers.

Which CR pump is used for reverse osmosis?

CRN, in 316 stainless. It is the standard high-pressure membrane feed pump for seawater and brackish-water RO.

Can Grundfos CR pumps handle hot water?

Yes — the standard range covers roughly −4 °F to 248 °F depending on seal and elastomer selection, which is why CR is common on boiler feed. Confirm the limit on the specific model's page, as it is set by the shaft seal and O-ring materials.

Do you stock these, or are they made to order?

Both. Each product page shows live availability, refreshed daily against Grundfos. Configurations held in a US warehouse show a stock status; the rest are built to order with a dispatch date.

Browse the range

CRE, CRIE & CRNE E-PumpsIntegrated variable speed CM & CME HorizontalCompact pressure boosting SP SubmersibleWells and groundwater BM Booster ModulesHigh-pressure RO boosting Repair Kits & SparesSeals, chambers, gaskets Need help sizing?Send us your duty point

ForeverPure Corporation is an authorized Grundfos distributor. If you have a flow and head figure, or an existing model number to cross-reference, send it over and we will confirm the right configuration before you order.