GRUNDFOS · VERTICAL MULTISTAGE PUMP END
CR 125 Pump End
Vertical multistage pump end in cast iron and 304 stainless steel, motor not included. 9 models from CR 125-1-1 to CR 125-4-2 for 15 to 75 HP NEMA motors (254TC to 365TSCZ frames), 6 in ANSI flanged ports, HQQE or HQQV cartridge shaft seal.
123-543 ft (53-235 PSI) Max Head · 858 GPM Max
Fits 15-75 HP NEMA Motors, Frame 254TC to 365TSCZ
6 in ANSI Ports
In-Line Suction and Discharge
232-363 PSI Max Operating Pressure
313-437 lb Weight
Overview
The CR 125 pump end is the hydraulic part of a Grundfos CR 125 vertical multistage pump, supplied without a motor: order it to rebuild an existing CR 125, to change the number of stages for a new duty, or to build a pump on a motor you already have. The pump head and base are cast iron; the impellers, chambers, shaft and other wetted parts are stainless steel (EN 1.4301, AISI 304). Suction and discharge sit on the same level, so it drops into a straight pipe run. The CR 125 is rated at 660 GPM (Grundfos rated flow); size it from the performance table below rather than from the model number.
- 9 models, CR 125-1-1 to CR 125-4-2, each built for a NEMA C-face motor of 15 to 75 HP (motor table below)
- 6 in ANSI flanges, 150 lb (CR 125-1-1 to CR 125-3) or 300 lb (CR 125-4-2)
- HQQE (EPDM) or HQQV (FKM) cartridge shaft seal with silicon-carbide faces
- Maximum operating pressure: 232-363 PSI by model
What Ships and What It Needs to Run
Included: the CR 125 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 (15 to 75 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 required, ordered separately. Grundfos supplies the companion connections as a separate 6 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 |
660 GPM (Grundfos rated flow) |
| Motor required |
NEMA C-face, 15 to 75 HP; frames 254TC, 284TSC, 326TSCZ, 364TSCZ, 365TSCZ (by model, see motor table) |
| Suction and discharge ports |
In-line; 6 in |
| Connections |
6 in ANSI flanges, 150 lb (CR 125-1-1 to CR 125-3) or 300 lb (CR 125-4-2) |
| Maximum operating pressure |
232-363 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.
CR 125-1-1 to CR 125-4-2 · 9 models
| Model |
0 GPM (Shut-off) |
171 GPM |
428 GPM |
641 GPM |
855 GPM |
| CR 125-1-1 |
53 |
53 |
47 |
35 |
17 |
| CR 125-1 |
71 |
67 |
62 |
52 |
34 |
| CR 125-2-2 |
101 |
101 |
93 |
69 |
33 |
| CR 125-2-1 |
119 |
117 |
110 |
88 |
52 |
| CR 125-2 |
138 |
135 |
127 |
106 |
71 |
| CR 125-3-2 |
168 |
167 |
158 |
125 |
71 |
| CR 125-3-1 |
187 |
185 |
175 |
143 |
90 |
| CR 125-3 |
205 |
202 |
192 |
161 |
108 |
| CR 125-4-2 |
235 |
233 |
222 |
178 |
106 |
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. 28 (water at 68 °F), and rounded down, at about 20%, 50% and 75% of 855 GPM, the last regular flow every curve in this listing reaches; the curves end at 858.8 GPM. Full curves are in the product images.
Motor each model needs (Grundfos price list and catalog; the motor is ordered separately):
| Model |
Motor HP |
NEMA frame |
| CR 125-1-1 |
15 |
254TC |
| CR 125-1 |
25 |
284TSC |
| CR 125-2-2 |
30 |
284TSC |
| CR 125-2-1 |
40 |
326TSCZ |
| CR 125-2 |
50 |
326TSCZ |
| CR 125-3-2 |
60 |
364TSCZ |
| CR 125-3-1 |
75 |
365TSCZ |
| CR 125-3 |
75 |
365TSCZ |
| CR 125-4-2 |
75 |
365TSCZ |
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: 232-363 PSI by model. |
| Liquid temperature |
Up to 248 °F with HQQE; up to 194 °F with HQQV. |
| Connections |
ANSI companion flanges (6 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 |
| Pump head and base |
Cast iron |
| Impellers, chambers, shaft |
Stainless steel EN 1.4301 (AISI 304) |
| Shaft seal faces |
Silicon carbide / silicon carbide (HQQ cartridge seal) |
| Seal and gasket rubber |
EPDM (HQQE) or FKM (HQQV) |
