Identification
Vertical in-line multistage centrifugal pump by Grundfos — the compact answer to high head: impellers stacked in series on a vertical shaft, suction and discharge aligned on the same pipe run, minimal footprint. A family of 16 sizes (CR 1s to CR 255) and material variants: CR (cast iron/stainless), CRI (304 stainless), CRN (full 316L). The CRE variant ships with a factory-integrated variable-frequency motor — the pump regulates its own speed to a pressure setpoint.
Position on the six axes
| Axis | Position |
|---|---|
| Hydraulics | Radial (low- stages) |
| Stages | Multistage — up to 36 |
| Configuration | Vertical in-line |
| Sealing | Sealed (cartridge seal) |
| Standard | — (catalog product; NEMA/IEC motors) |
| Service | Utilities, pressure boosting, industrial water, RO |
Ranges and construction
| Parameter | Catalog value |
|---|---|
| Flow | up to ~340 m³/h (1,500 gpm) |
| Head | up to ~280 m (910 ft) |
| Temperature | −15 °C to +90 °C (standard, per seal) |
| Materials | cast iron · 304 · 316L |
Stamped stainless stages (high efficiency in a small machine), a top-accessible quick-swap cartridge mechanical seal, rigid split coupling. The stages' accumulated axial thrust is carried by the motor bearing — sized for it by the manufacturer.
Line variants
| Variant | Wetted material / what it solves |
|---|---|
| CR | Cast iron + stainless — water and general utilities |
| CRI | 304 stainless — mildly aggressive liquids |
| CRN | Full 316 stainless — chemicals and process |
| CRT | Titanium — seawater, chlorides and severe chemicals |
| CRE / CRIE / CRNE | Any of the above with the E-motor (factory-integrated VFD, setpoint control) |
| CRNE-HS | High speed — very high pressure with fewer stages |
| CRN-SF | Super-finished internal surfaces — high pressure (systems up to ~50 bar) for water treatment |
Differentials and points of attention
- LiqTec: factory protection against dry running and overtemperature — the architecture's no. 1 sensitivity handled by the manufacturer itself.
- Top-access cartridge seal: replacement without unstacking the stages or removing the motor — the line's maintainability argument.
- Grundfos Product Center: online selection and curves per duty point — verifiable sizing before purchase.
- Point of attention: the stack's axial thrust is carried by the MOTOR bearing — the line is designed for Grundfos motors (MG/MGE); substituting a generic motor requires verifying the thrust bearing.
Where it stands out / limitations
Stands out in boosting and utilities: high head without extreme speed, minimal vertical footprint, and the electronics ecosystem (CRE + sensors + BMS) that makes the off-the-shelf "smart pumping system" — the opposite end of the spectrum from the API process pump. Limitations: clean, cool fluids (stamped stages do not tolerate solids; limited thermal range); stage maintenance requires unstacking; not a platform for severe process or O&G standards.
Official documentation
- CR family page — Grundfos Product Center — variants, curves and online sizing.
- CR/CRI/CRN data booklet (official PDF) — ranges, curves and limits per size (D05 — official source).
Reliability
No published MTBF (the industry rule). The failure profile shifts with the architecture: fewer alignment/baseplate problems (in-line, rigid coupling), a quick-swap cartridge seal — and sensitivity concentrated in water quality (abrasives in the stages) and, on the CRE, in the power electronics. General benchmarks and the failure hierarchy in "Reliability in numbers" in the Centrifugal Pump handbook.