What is the Grundfos NBG 150-125-315/336?
Grundfos identifies this NBG configuration in its Digital Realty case study as the pump selected to lift water from Millwall Inner Dock through the primary heat-exchanger circuit. The supplier describes a close-coupled, single-stage unit with an IE3 motor and variable-speed drive. The case establishes a demanding source-water use, but it does not publish the final flow, head, redundancy or measured seasonal efficiency. A new project should not reuse the model from the reference alone. It must recalculate suction conditions, screen and fouling losses, corrosion materials and environmental limits. The duty and standby arrangement and service access also need review. Source-water service requires explicit treatment of debris screens, biological fouling, corrosion, low-water conditions and environmental discharge limits that may not apply to a closed rack loop. Obtain the selected pump curve, net positive suction head requirement and minimum continuous flow. The submittal should also identify materials, seal arrangement and drive-control sequence. The acceptance plan should verify lifting duty at worst water level and fouled-system resistance, plus automatic transfer to standby equipment. The cited evidence gives no installed quantity or maintenance history, so current operator references and service records remain necessary.