Roll over image to zoom
SKU: 93209296
Grundfos NB 50-125/138 Cast Iron 0.75 kW End Suction Centrifugal Pump with Closed Impeller
Australia-Wide
(08) 9240 2992
Official Grundfos
Peace of Mind
Product Overview
Secondary heating distribution lines in plant facilities rely on the Grundfos NB 50-125/138 centrifugal pump. Fitted with a 0.75 kW motor, system piping interfaces through an axial DN 65 suction port and a radial DN 50 discharge flange.
Discharge throughput reaches approx. 796 L/Min operational volume while reaching a approx. 6.4 m maximum head. Housing construction features cataphoretically coated EN-GJL-250 cast iron, accommodating a stainless steel impeller and a BQQE mechanical seal. Net weight measures 42 kg.
At a rated feed of 415 V three-phase, the motor draws 1.6 Amps to deliver 0.75 kW rated mechanical power. Fluid temperature capabilities range from -25°C to 120°C under working pressure limits up to 16 bar. Flange interfaces are dimensioned at DN 65 inlet and DN 50 outlet.
Motor casing construction provides IP55 ingress sealing and Class F winding insulation. External motor overload protection must be provided by the installer. The back-pull-out construction allows extraction of the motor and rotating components without disturbing suction or discharge pipe connections.
Features
- Solid stub shaft configuration supported by deep groove ball bearings absorbs axial thrust loads.
- Standardized EN1092-2 PN16 flange dimensions match standard commercial and district pipe manifolds.
- High-efficiency IEC electric drive motor maximum flow of S1 continuous operation in ambient conditions up to 40°C.
- Back-pull-out construction allows drive and impeller removal without disconnecting suction or discharge lines.
- Precision balanced rotor and runner assemblies minimize operating vibration across all pump speeds.
- Cast iron volute casing with integral mounting feet absorbs hydraulic forces and pipework stresses.
- Replaceable wear rings retain correct internal hydraulic clearances over long operating periods.
SPECIFICATIONS
| Max Flow | 796 L/Min |
| Max Head | 6.4 m |
| Power | 0.75 kW / 415v |
| Rated Current | 1.6 Amps |
| Suitable For | Facility Fluid Transfer & Circulation |
| 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.
What operating temperature boundaries and pressure limits are specified?
Pressure ratings up to 16 bar and fluid temperatures from -25°C to 120°C are supported across the Grundfos NB 50-125/138.
How is routine mechanical maintenance managed without disturbing facility pipe headers?
Routine plant servicing is simplified on the NB 50-125/138 by its back-pull-out layout, allowing drive extraction without dismantling pipework.
How much liquid delivery and dynamic pressure does this pump sustain?
The NB-50-125-138 provides approx. 796 L/Min in fluid flow and approx. 6.4 m in dynamic head, depending on system pressure demands.
What casing and impeller metallurgy protects this pump in utility service?
High-grade EN-GJL-250 cast iron forms the casing of the NB 50 125 138, housing a stainless steel impeller for lasting service.
What electrical supply and running current are needed for this motor?
The NB/50/125/138 is driven by a 0.75 kW motor running on a 415 V three-phase supply, drawing approximately 1.6 Amps with IP55 protection.
Need help choosing the right pump?
Our team of pump experts are here to help you find the perfect solution for your application.
- Free expert advice
- Pump sizing & system recommendations
- Fast response — call or email us