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SKU: 93209292
Grundfos NB 50-125/121 Cast Iron 4 kW End Suction Centrifugal Pump with Closed Impeller
Australia-Wide
(08) 9240 2992
Official Grundfos
Peace of Mind
Product Overview
Specified for commercial building services, process water loops, and district cooling infrastructure, the NB 50-125/121 end-suction centrifugal pump incorporates DN 65 suction and DN 50 discharge flanged ports. The end-suction volute design connects directly to suction line headers and concrete foundation bases.
At nominal operational speed, hydraulic output provides approx. 1161 L/Min flow throughput alongside a maximum head limit of approx. 19 m. Structural construction incorporates an EN-GJL-250 cast iron body with cataphoresis surface finish. Internal components feature a stainless steel impeller and BQQE seal. Total net weight stands at 71 kg.
The NB 50-125/121 electric motor operates on a 415 V three-phase supply drawing 7.82 Amps rated current at 4 kW output power. Fluid handling parameters accommodate liquid temperatures between -25°C to 120°C up to 16 bar system pressure. Line connection uses opposite DN 65 inlet and DN 50 outlet flanged ports.
Enclosure protection on the NB 50-125/121 model meets IP55 standards while motor windings feature Class F insulation and PTC thermistor protection relays. Maintenance technicians can extract the drive unit using back-pull-out access without removing the cast iron volute casing from connected plant room piping manifolds.
Features
- EN733 and ISO2858 dimensional compliance ensures interchangeability with other standard end-suction pumps across commercial and industrial installations.
- ATEX Zone 1, 2, 21 or 22 certification available for operation in potentially explosive atmospheres (except E-model variants).
- Integrally cast suction and discharge ports with dedicated vent and drain ports provide direct connection points without additional fittings.
- No baseplate or grouting required to maintain correct shaft alignment and vibration levels within Hydraulic Institute standards.
- Cataphoretic electrocoating on cast iron internal surfaces provides barrier protection against oxidative corrosion in hydronic circulation loops.
- Close-coupled configuration eliminates coupling alignment procedures and reduces overall installation footprint compared to long-coupled alternatives.
- Ball bearing support arrangement accommodates both radial and axial thrust loads generated during continuous duty operation at rated speed.
IMPORTANT: Bulk freight charges apply. Please contact us for a freight quote before ordering.
SPECIFICATIONS
| Max Flow | 1161 L/Min |
| Max Head | 19 m |
| Power | 4 kW / 415v |
| Rated Current | 7.82 Amps |
| Suitable For | Industrial Process Water Loops |
| Body Material | Cast Iron |
| Liquid Temperature | -25°C to 120°C |
| Inlet Size | 65 mm |
| Outlet Size | 50 mm |
| Warranty | 24 Months |
Warranty & Returns
All products supplied by Foundation Pumps are covered by a minimum 12-month warranty unless otherwise stated. Some brands may offer longer manufacturer warranties. Warranty covers manufacturing defects, faulty materials and workmanship under normal use.
- Products must be installed correctly and in accordance with the manufacturer’s instructions.
- Warranty does not cover incorrect installation, misuse, dry running, normal wear and tear, unauthorised repairs or damage caused by external factors.
- Proof of purchase, photos, videos and installation details may be requested when assessing a warranty claim.
- The customer is responsible for returning the product to Foundation Pumps or the nominated service centre unless otherwise agreed.
- Removal, reinstallation, labour and associated site costs are generally the customer’s responsibility unless required under Australian Consumer Law.
- Change-of-mind returns may be accepted within 30 days provided the product is unused, uninstalled and returned in its original packaging.
- Customers are responsible for return freight costs for change-of-mind returns.
- Restocking fees may apply to special-order, bulky or non-stocked products.
- Used, installed or specially ordered products may not be eligible for change-of-mind returns.
- If a product arrives damaged or faulty, please contact Foundation Pumps as soon as possible so we can assist with the appropriate repair, replacement or refund.
Your rights under Australian Consumer Law are not affected.
Can this pump operate in warm or hot water without overheating?
Liquid operating limits establish that the Grundfos NB 50-125/121 accommodates temperatures -25°C to 120°C during standard duties.
How high can this pump lift water vertically?
Dynamic lift generated by the NB 50-125/121 reaches a maximum elevation head of approximately approx. 19 m across discharge lines.
What maximum flow rate does this pump achieve during heavy influx?
Displacing fluid into connected headers, the NB-50-125-121 sustains approx. 1161 L/Min of volumetric throughput.
What metallurgy is selected for the pump body to resist abrasive wear?
Durable EN-GJL-250 construction gives the NB 50 125 121 exceptional structural strength and long-term protection against corrosive fluids.
How much power does the motor consume during standard operation?
Powered by a dedicated 4 kW motor, the NB/50/125/121 connects to 415 V three-phase mains power with a rated current draw of 7.82 Amps.
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