The Alfa Laval SRU rotary lobe pump is a positive displacement pump for gentle handling of sensitive process fluids in demanding hygienic applications. High-precision rotors and low-shear, low-pulsation pumping action ensure reliable, continuous performance and superior energy efficiency. Its contamination-proof design ensures compliance with the most stringent hygienic design standards and the requirements for Cleaning-in-Place (CIP) and Sterilization-in-Place (SIP) validation.

SRU rotary lobe pump

High pump efficiency and gentle product treatment optimize contamination-free transfer of viscous products

  • Maximize uptime through consistent performance
  • Raise product quality due to gentle, low-shear product handling
  • Increase product safety and quality due to hygienic design and validated cleaning processes
  • Add more process flexibility with versatile handling and efficient pumping of various products, including viscous media
  • Low-maintenance design – a robust gearbox construction with heavy-duty shafts, torque locking assemblies and taper roller bearings minimizes service

The Alfa Laval SRU rotary lobe pump provides high-efficiency fluid transfer, maximizing uptime while minimizing contamination risks and maintenance costs. Its low-pulsation, low-shear pumping action transfers media of varying viscosities with ease. Modular design provides great flexibility to tailor a pump to meet specific process requirements.

Available with 12 different pump head displacements, the SRU rotary lobe pump handles flow rates up to 106 m3/h, differential pressures up to 20 bar and temperatures up to 200°C.

Consistent performance

The reliable SRU rotary lobe pump features a front cover seal with defined compression, rotor nut retention design, drainable pump head and ultra-clean surface finishes to maximize uptime and minimize contamination risks.

Greater flexibility

Modular design and a broad range of models, capacities and options provide versatility to meet specific application and process requirements. 

Low maintenance

A robust gearbox construction with heavy-duty shafts, torque locking assemblies and tapered roller bearings minimizes maintenance requirements.

Certification, specifications, and standards

SRU rotary lobe pumps meet the requirements of global hygienic standards, including 3-A Sanitary Standards and FDA standards. The pumps can also meet ATEX requirements for use in explosive environments.


Product benefits

  • Consistent performance
  • Minimal risk of contamination
  • Low maintenance

How it works


The pumps operate with no internal contact parts in the pump head. The standard materials of construction are 316L stainless steel for all wetted parts and painted cast iron for the gearbox. Other materials are available upon request.

Operating principle

A gear train in the SRU rotary lobe pump gearbox drives the rotors and provides accurate synchronization, or timing, of the rotors. The movement of the contra-rotating rotors creates a partial vacuum that allows atmospheric pressure or other external pressures to force fluid into the pump chamber.

Fluid is carried through the pump in the cavities formed between the dwell of the rotor and the interior of the rotor case. As the rotor blades disengage, each dwell forms a cavity that expands, filling with fluid. As the rotor blades engage, the cavity diminishes, displacing fluid into the outlet port.


  • Bi-lobe rotors
  • SRU mounted on a base plate complete with coupling, guard, gear motor and shroud for easy plug-and-play installation
  • Single, single flushed and double mechanical seals
  • Different materials for mechanical seals to suit the fluid being pumped and/or application requirements
  • Horizontal or vertical porting
  • Heating/cooling saddles and jackets
  • Integrated pressure relief valve
  • Rectangular inlet for transfer of high viscosity fluids
  • Material traceability to EN10204 3.1
  • ATEX compliance

360° Service and maintenance videos

Alfa Laval SRU rotary lobe pumps - dismantle, seals and fittings

Alfa Laval Service Kits

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Alfa Laval offers a comprehensive range of pumps intended for hygienic applications in the dairy, food, beverage, home care, personal care, biotechnology and pharmaceuticals.

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CAD portal

Download the product models in Neutral or Native CAD file formats. It is also possible to download 3D PDF files.

 View CAD portal 




Visit the animations site and take a look inside a product to see and understand how it works. 

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