GRUNDFOS · VERTICAL MULTISTAGE PUMP END
CRN 255 Pump End
Vertical multistage pump end in 316 stainless steel, motor not included. 12 models from CRN 255-1-1 to CRN 255-4-1 for 60 to 300 HP NEMA motors (364TSC to 449TSD frames), 8 in ANSI flanged or 8 in Victaulic-type ports, HQQE or HQQV cartridge shaft seal.
199-909 ft (86-393 PSI) Max Head · 1,752 GPM Max
Fits 60-300 HP NEMA Motors, Frame 364TSC to 449TSD
8 in ANSI or 8 in Victaulic Ports
In-Line Suction and Discharge
232-580 PSI Max Operating Pressure
556-816 lb Weight
Overview
The CRN 255 pump end is the hydraulic part of a Grundfos CRN 255 vertical multistage pump, supplied without a motor: order it to rebuild an existing CRN 255, to change the number of stages for a new duty, or to build a pump on a motor you already have. Every part in contact with the liquid is stainless steel (EN 1.4401, AISI 316). Suction and discharge sit on the same level, so it drops into a straight pipe run. The CRN 255 is rated at 1350 GPM (Grundfos rated flow); size it from the performance table below rather than from the model number.
- 12 models, CRN 255-1-1 to CRN 255-4-1, each built for a NEMA C-face motor of 60 to 300 HP (motor table below)
- 8 in ANSI flanges, 150 lb (CRN 255-1-1 to CRN 255-2-1) or 300 lb (CRN 255-2 to CRN 255-4-1), with a cast iron flange and base plate that do not touch the liquid (CRN 255-1-1 to CRN 255-4-1); or 8 in Victaulic-type grooved ends, with a cast iron base plate that does not touch the liquid (CRN 255-1-1 to CRN 255-4-1)
- HQQE (EPDM) or HQQV (FKM) cartridge shaft seal with silicon-carbide faces
- Maximum operating pressure: ANSI versions 232-580 PSI; Victaulic versions 363-580 PSI (by model)
What Ships and What It Needs to Run
Included: the CRN 255 pump end and the motor coupling (Grundfos price list).
Motor required, ordered separately. A NEMA C-face motor at the horsepower and frame shown for your model in the motor table under Models & Performance (60 to 300 HP), with the starter or drive that motor needs. Grundfos specifies a smooth-shaft motor, or a keyed shaft with a half key, for balanced running (price list).
ANSI companion flanges or Victaulic couplings required, ordered separately. Grundfos supplies the companion connections as a separate 8 in set (Grundfos price list).
Suction and discharge piping, valves and controls: sized to your system and ordered separately.
Genuine Grundfos equipment, factory-new in original packaging — sold and supported by Watermain Supply, an independent industrial supplier.
Warranty: 24 months from date of installation, but not more than 30 months from date of manufacture (Grundfos limited warranty). Grundfos repairs or replaces its own product; costs of removal, installation and transportation are not covered, and products sold but not manufactured by Grundfos carry their own manufacturer’s warranty.
Specifications
| Specification |
Value |
| Product |
Pump end only: hydraulic assembly and motor coupling, motor not included |
| Rated flow at 60 Hz |
1350 GPM (Grundfos rated flow) |
| Motor required |
NEMA C-face, 60 to 300 HP; frames 364TSC, 405TSD, 444TSD, 445TSD, 447TSD, 449TSD (by model, see motor table) |
| Suction and discharge ports |
In-line; 8 in |
| Connections |
8 in ANSI flanges, 150 lb (CRN 255-1-1 to CRN 255-2-1) or 300 lb (CRN 255-2 to CRN 255-4-1), with a cast iron flange and base plate that do not touch the liquid; 8 in Victaulic-type grooved ends |
| Maximum operating pressure |
ANSI versions 232-580 PSI; Victaulic versions 363-580 PSI (by model) |
| Liquid temperature |
Up to 248 °F with HQQE; up to 194 °F with HQQV |
| Shaft seal |
HQQE (EPDM) or HQQV (FKM) cartridge seal, SiC/SiC faces |
| Pump orientation |
Vertical |
| Frequency |
60 Hz |
| App |
None: a mechanical pump end with no electronics |
Models & Performance — Will It Do What You Need?
Find the pressure you need at your flow and pick the first model that reaches it. Pressure at flow in PSI, one row per model.
CRN 255-1-1 to CRN 255-4-1 · 12 models
| Model |
0 GPM (Shut-off) |
350 GPM |
875 GPM |
1,313 GPM |
1,750 GPM |
| CRN 255-1-1 |
86 |
84 |
78 |
60 |
28 |
| CRN 255-1 |
107 |
103 |
98 |
83 |
55 |
| CRN 255-2-2 |
167 |
165 |
154 |
121 |
54 |
| CRN 255-2-1 |
187 |
184 |
174 |
143 |
81 |
| CRN 255-2 |
209 |
209 |
199 |
169 |
111 |
| CRN 255-3-3 |
249 |
247 |
231 |
182 |
81 |
| CRN 255-3-2 |
268 |
265 |
250 |
204 |
107 |
| CRN 255-3-1 |
290 |
290 |
274 |
229 |
136 |
| CRN 255-3 |
314 |
314 |
298 |
253 |
165 |
| CRN 255-4-3 |
349 |
346 |
326 |
264 |
132 |
| CRN 255-4-2 |
371 |
370 |
350 |
289 |
162 |
| CRN 255-4-1 |
393 |
394 |
374 |
313 |
190 |
Pressure the pump end develops at each flow, in PSI, rounded down (feet = PSI × 2.31), with the motor shown in the motor table. Shut-off is Grundfos’s published maximum head for each model. Flow columns are digitized from the published 60 Hz curve in the CR, CRN 95-255 Data Booklet (60 Hz, 2026), p. 46 (water at 68 °F), and rounded down, at about 20%, 50% and 75% of 1,750 GPM, the last regular flow every curve in this listing reaches; the curves end at 1,752.8 GPM. Full curves are in the product images. On CRN 255-3, CRN 255-4-1 the curve reads above the published shut-off at low flow (by up to 3 ft); the published shut-off is kept and the flow columns follow the curve.
Motor each model needs (Grundfos price list and catalog; the motor is ordered separately):
| Model |
Motor HP |
NEMA frame |
| CRN 255-1-1 |
60 |
364TSC |
| CRN 255-1 |
100 |
405TSD |
| CRN 255-2-2 |
125 |
444TSD |
| CRN 255-2-1 |
150 |
445TSD |
| CRN 255-2 |
200 |
447TSD |
| CRN 255-3-3 |
200 |
447TSD |
| CRN 255-3-2 |
200 |
447TSD |
| CRN 255-3-1 |
250 |
449TSD |
| CRN 255-3 |
250 |
449TSD |
| CRN 255-4-3 |
250 |
449TSD |
| CRN 255-4-2 |
300 |
449TSD |
| CRN 255-4-1 |
300 |
449TSD |
Before You Buy — The Limits That Decide the Fit
| Check |
What decides the fit |
| Motor |
Order a NEMA C-face motor at the HP and frame Grundfos lists for your model in the motor table under Models & Performance. Use a smooth-shaft motor or a keyed shaft with a half key (Grundfos price list). |
| Duty point |
The model’s pressure at your flow must cover the system’s total head; the shut-off column is Grundfos’s published maximum head, the most the model can make. |
| Working pressure |
Inlet pressure plus the pressure the pump adds must stay within the maximum operating pressure: ANSI versions 232-580 PSI; Victaulic versions 363-580 PSI (by model). |
| Liquid temperature |
Up to 248 °F with HQQE; up to 194 °F with HQQV. |
| Connections |
ANSI companion flanges or Victaulic couplings (8 in) ordered separately. Match the connection to the existing pipework. |
| Shaft seal |
HQQE has EPDM rubber parts and HQQV has FKM; choose the rubber that suits the pumped liquid. |
Applications
HVAC heating and air conditioning, district heating and cooling, plumbing pressure boosting, industrial water supply and transfer, process liquids, wash and clean, water treatment, irrigation and ground water transfer (Grundfos CR range applications).
Materials of Construction
| Component |
Material |
| All wetted parts |
Stainless steel EN 1.4401 (AISI 316) |
| Base plate; flange (ANSI versions) |
Cast iron, not in contact with the pumped liquid |
| Shaft seal faces |
Silicon carbide / silicon carbide (HQQ cartridge seal) |
| Seal and gasket rubber |
EPDM (HQQE) or FKM (HQQV) |
