Grundfos NBS/NBSE Split-Coupled End Suction Pumps

Grundfos NBS/NBSE Split-Coupled End Suction Pumps for Commercial HVAC, District Energy, Industrial, and Water Utility Systems

Grundfos NBS/NBSE Split-Coupled End Suction Pumps are single-stage centrifugal pumps designed for commercial HVAC, hydronic heating and cooling, district energy, industrial water, and water utility applications. Combining end-suction hydraulics with a compact split-coupled design, the NBS/NBSE range provides an alternative to traditional frame-mounted pumps where installation space, efficiency, alignment, and serviceability are important.

The Grundfos NBS is the fixed-speed configuration within the range. Unlike conventional frame-mounted long-coupled pumps, the NBS uses machined registered fits and a rigid split-coupling arrangement that maintains alignment between the pump and motor. No baseplate grouting or pump-to-motor alignment is required, helping reduce installation time and associated field labor. The optimized design can also provide up to a 35% smaller footprint than traditional frame-mounted pump arrangements.

Serviceability is another major advantage of the NBS/NBSE platform. A spacer-coupling and back pull-out design provides access to the mechanical seal without requiring removal of the motor or disturbing the connected piping. Grundfos also uses silicon carbide/silicon carbide hard-faced mechanical seals on NBS pumps to improve wear resistance and support longer service intervals in demanding systems.

For systems with variable flow requirements, Grundfos NBSE pumps add electronically controlled motor and drive technology to the split-coupled platform. It's a high-efficiency E-pump solution with an integrated drive and onboard controls, allowing pump speed to be adapted to actual system demand. This makes NBSE pumps particularly useful in variable-flow HVAC and other applications where reducing pump output during partial-load operation can improve overall system efficiency.

Features

• Single-stage end-suction centrifugal pump design
• Split-coupled pump and motor configuration
• ANSI pump configuration for North American applications
• NBS fixed-speed configurations available
• NBSE electronically controlled variable-speed configurations available
• No pump-to-motor field alignment required
  
• No traditional baseplate grouting required
• Up to 35% smaller footprint compared with traditional frame-mounted pump designs
• Back pull-out construction simplifies pump service
• Spacer coupling provides easier mechanical seal access
• Mechanical seal can be serviced without removing the motor or disturbing system piping
• Stainless steel impeller design helps improve hydraulic efficiency
• Balanced impeller design helps reduce vibration and noise
• Integrally cast diffuser vane helps reduce hydraulic turbulence
• Top centerline discharge supports self-venting and compact piping layouts
• Suitable for fixed-speed and variable-demand pumping systems
• Designed for efficient installation, reliability, and long-term serviceability

Applications

• Commercial HVAC systems
• Hydronic heating systems
• Hydronic cooling systems
• Chilled water circulation
• Condenser water systems
• District heating
• District cooling
• District energy systems
• Central utility plants
• Commercial mechanical rooms
• Industrial water circulation
• Industrial process water
  
• Water utility systems
• Building services
• Institutional facilities
• Variable-flow HVAC systems
• Fixed-speed water circulation
• Pump replacement and retrofit projects
• Applications requiring a compact alternative to frame-mounted end-suction pumps