SRU

With its smooth, low-shear pumping action, the SRU is Alfa Laval’s core rotary lobe pump for the gentle handling of sensitive process fluids within the dairy, food and beverage, biotechnology and pharmaceutical industries.

SRU rotary lobe pump

Alfa Laval SRU rotary lobe pumps are carefully engineered to provide reliable performance, trouble-free operation and superior energy efficiency for demanding applications. It is an excellent choice for duties that require contamination-proof pumps to meet high standards of hygiene, low-shear and low-pulsation operation. This EHEDG-approved pump handles both Cleaning in Place and Sterilization in place, and can be supplied with thorough documentation to support rigorous validation requirements.

For even more demanding hygienic and ultra-clean duties, Alfa Laval offers the SX rotary lobe pump.

Consistent performance, minimal risk of contamination

SRU rotary lobe pumps are designed with features that maximize performance and minimize the risk of contamination. These include a defined compression front cover sealing, rotor nut retention design, drainable pump head and ultra-clean surface finishes.

Safeguarding product quality

Understanding of flow patterns is vital to ensure high efficiency fluid transfer with low pulsation, low shear and low noise characteristics. Alfa Laval employs Computational Fluid Dynamics (CFD) to establish exact geometry for the rotors and rotor case.

Greater flexibility and application fit

The modular design of the SRU provides greater flexibility to configure exactly the right solution for specific process requirements.

To meet different process requirements, the SRU features an R90 external shaft seal, which may be specified in various materials and configurations in order to ensure the correct shaft seal for the application. Alternatively the SRU can be fitted with Hyclean mechanical seals as well as other seal solutions.

In addition to a broad range of models and capacities available in horizontal or vertical porting, the SRU has a wide selection of options, including standard and custom seals, heating/cooling saddles and jackets, an integrated pressure relief valve and a rectangular inlet for pumping high viscosity fluids.

Robust construction – low maintenance

To deliver reliable operation and low maintenance the SRU features a robust gearbox construction with heavy-duty shafts, torque locking assemblies and taper roller bearings throughout.

Supply and delivery

The SRU range is available with twelve different pump head displacements, flow rates up to 106 m³/h, differential pressures up to 20 bar, temperatures up to 200°C and port sizes from 25 to 150 mm in diameter.

Certification, specification and standards

SRU rotary lobe pumps comply with EHEDG, 3-A, 3.1 and FDA hygienic standards and have ATEX approval for use in explosive environments. For more information, please consult the documentation provided.

                                            SRU - How it works

Product benefits

  • Consistent performance
  • Minimal risk of contamination
  • Low maintenance

How it works

Construction

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.

Options

  • 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

 Rotary lobe pump - operating principle

The movement of the counter rotating rotors creates a partial vacuum that allows atmospheric pressure or other external pressures to force fluid into the pump chamber. As the rotors revolve, an expanding cavity forms, filling with fluid. As the blades disengage, each dwell forms a cavity. As the rotor blades engage, the cavity diminishes and fluid is, displaced into the outlet port.

360° Service and maintenance videos

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

Alfa Laval Service Kits

Part of a broad pump range

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

For a broader pump range, explore the different product categories: Centrifugal pumpsCircumferential piston pumps and Twin Screw.

Juice pasteurization: How to improve energy efficiency and cut total cost of ownership?

In this technical article, learn about the impact of fruit juice viscosity on energy consumption, and how to achieve cost savings and greater process flexibility.

Citrus 640x360

Food Logic

Alfa Laval's hygienic equipment combines high performance with gentle handling to preserve sensitive ingredients. Keeping up with the food industry trends and addressing four key challenges; supplying food products to consumers at a competitive price, getting the most from raw materials, reducing waste and emissions, and delivering safe and hygienic food products.

food logic 640x360

Product catalogue

Alfa Laval's hygienic equipment product catalogue "Close at hand" includes product leaflets, performance curves, links to animations, brochures and price lists for ordering purposes.

Close at hand 2019 - Cover image 640x360

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 

Animations

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

View animations 

Pumps

Pumps for hygienic use brochure

Learn more

 

 

 

near Newsletter

To keep you updated on important sustainability issues and opportunities in your industry and processes.

Learn more

Technical articles