Alfa Laval SRU Series Pumps

Alfa Laval's SRU rotary lobe positive displacement pump features a smooth, low shear pumping action. The SRU is Alfa Laval's core rotary lobe pump for the gentle handling of sensitive process fluids.

This EHEDG-approved pump handles both clean-in-place (CIP) and sterilization-in-place (SIP), and can be supplied with thorough documentation to support rigorous validation requirements. The advanced Hyclean™ seal technology of the SRU series combines versatility with easy maintenance.


  • SRU1
  • SRU4
  • SRU2
  • SRU5
  • SRU3
  • SRU6

The SRU range of rotary lobe pumps has been designed for use on a wide range of applications within the brewing, dairy, food, pharmaceutical, and chemical industries. The SRU pump can handle low to high viscosity media, is suitable for CIP and SIP, and conforms to 3-A sanitary standards. The characteristic smooth, low-shear pumping action is ideal for products such as creams, gels, emulsions, aerated mixtures, delicate cells, and organic solids in suspension.

The SRU range is compact in size and highly efficient, capable of flow rates up to 466 gpm and pressures up to 290 psig. The new, improved modular design provides for greater application flexibility and cost-effective easy maintenance.

Standard Design

The SRU pump, with its conventional lobe pump design concept, has a robust cast iron gearbox, which provides maximum shaft rigidity and easy oil seal replacement. The SRU range in series 1 – 4 has a universal gearbox design. This offers flexibility when mounting pumps, allowing the inlet and outlet ports to be in either a vertical or horizontal plane by changing the foot position. The SRU range in series 5 & 6 has dedicated gearbox castings, which also allows the inlet and outlet ports to be in either the vertical or horizontal plane. A quality epoxy paint system is used on the gearbox exterior for optimum protection against natural and corrosive elements.

Pumphead Construction

The SRU, in standard specification, has sanitary design full-bore inlet and outlet ports to International Standards, maximizing inlet and outlet port efficiency and NPSH characteristics. Enlarged diameter and rectangular ports are also available to handle very high viscosity products.

The SRU, in standard specification, has tri-lobe rotors with the option of bi-lobe rotors for handling fluids containing large delicate solids. All rotors are available in three temperature ratings allowing the pump to be operated at maximum process temperatures of 158°F, 266°F, and 392°F for both fluid-pumped and CIP.

Pump Sizing

To correctly size a rotary lobe pump some essential information is required. Provision of the information listed below enables our customer support personnel to determine the optimum pump selection:

  • Fluid to be pumped
  • Viscosity
  • SG/Density
  • Pumping temperature — minimum, normal, and maximum
  • CIP temperature(s) — minimum, normal, and maximum
Working Principle

The positive displacement of the SRU pump is provided by non-contacting, contra-rotating tri-lobe or bi-lobe rotors within a fully swept pump chamber. All SRU pumps are capable of bi-rotational flow without modification.

Pump GearboxHigh quality grey cast iron
PumpheadProduct wetted components in 316L and 329L
Product Wetted ElastomersUSP Class VI EPDM, NBR, FPM all FDA conforming. Also PTFE for chemical applications.
Maximum Solid Size Capability
Pump ModelMax Size of Spherical Solids - Bi-lobe Rotors


Max Size of Spherical Solids - Tri-lobe Rotors


Pump ModelBare Shaft Pump - Horizontal Porting


Bare Shaft Pump - Vertical Porting



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