DescriptionFeaturesDetailsHow It WorksDocumentation



Built from the ground up for hygienic applications, the SX is Alfa Laval’s premium rotary lobe pump. It is designed for gentle transportation of process fluids and is perfect for hygienic and ultra-clean applications in the biotechnology and pharmaceutical industries, health and beauty, and demanding food applications.

With the SX’s multi-lobe rotor geometry, it offers low pulsation and gentle pumping. This makes it the best choice for transporting sensitive products that require gentle handling to minimize shearing.

This EHEDG-approved pump is designed for both Clean-in-Place (CIP) and Sterilization-in-Place (SIP).


  • SX1
  • SX2
  • SX3
  • SX4
  • SX5
  • SX6
  • SX7

Related Industries:

Processed Foods, High-Acid Foods, Dairy, Beverages, Brewery, Home & Personal Care, Pharmaceutical, Biotech, Chemical


Protecting end-product quality

Low pulsation, low shear and low noise characteristics, while ensuring efficient fluid transfer, are trademarks for the SX pump. This high level of performance has been achieved through a detailed understanding of flows and the exact geometry of the rotors and rotor case. For this Alfa Laval employs Computational Fluid Dynamics (CFD).

Enhanced cleanability

SX rotary lobe pumps are designed with features that maximize performance and minimize the risk of contamination. These include a low-profile rotor nut, hygienic front-loading mechanical seals, defined compression front cover sealing, fully drainable pump head with 3° fall angle, and sanitary or ultra-clean surface finishes.

Cleanablity hand-in-hand with low maintenance

Designed for maximum cleanability and ease of access, the SX pump is a low maintenance solution. Alfa Laval manufactures all pump parts, including the rotor case and high-precision rotors. This facilitates maintenance and guarantees full interchangeability of spare rotor parts.

For reliable operation and lower maintenance the robust gearbox construction comes with heavy-duty shafts, torque locking assemblies and taper roller bearings throughout. The gearbox’s universal design provides the flexibility of mounting the pumps with inlet and outlet ports in vertical or horizontal position.

Supply and delivery

Available in 14 different models, SX rotary lobe pumps are capable of handling of a wide variety of viscosity and temperature requirements, flow rates up to 115 m3/h, pressures up to 15 bar and temperatures up to 150°C. A wide range of seals is available to ensure that the right seal is selected for the specific application.

Certification, specification and standards

All SX 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.


The SX range of rotary lobe pumps has been designed for use on a wide variety of applications within the pharmaceutical, biotechnology, fine chemical, and speciality food industries. Being certified by EHEDG (European Hygienic Equipment Design Group) as fully CIP’able to their protocol, the SX range is ideally suited to applications where cleanability and corrosion resistance is paramount.

In addition, the SX pump range also conforms to USA 3-A sanitary standards and all media contacting components are FDA compliant. The SX pump operates with a high efficiency, low shear pumping action for assured gentle handling of delicate and sensitive media.

The SX pump range is also classified for use in potentially explosive atmospheres under the ATEX Directive 94/9/EC Group II, Categories 2 & 3, with temperature classification T1 to T4.

The SX range is compact in size, and can handle flow rates up to 506 gpm and pressures up to 218 psi.


The SX 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 SX range in series 1 – 4 has a universal gearbox design. This gives the flexibility of mounting pumps with the inlet and outlet ports in either a vertical or horizontal plane, by changing the foot and its position.

The SX range in series 5 & 6 has dedicated gearbox castings, which also allow the inlet and outlet ports to be in either the vertical or horizontal plane. The SX series 7 has a dedicated gearbox casting allowing inlet and outlet ports in a vertical plane only.


The SX pump has sanitary design full bore inlet and outlet ports to International Standards, maximizing inlet and outlet port efficiency and NPSH characteristics. Vertical porting and unique rotorcase internal profile enhances self-draining and self-venting while maintaining optimum volumetric efficiency.

The SX pump has four lobe rotors, designed using CFD (Computational Fluid Dynamics) to develop the optimum rotor geometry – possibly the first rotary lobe pump to be developed using this technology. All rotors are rated to 302°F facilitating use with CIP/SIP processes.


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
Pump Series Max Size of Spherical Solids(in)
SX1 0.28
SX2 0.39
SX3 0.51
SX4 0.63
SX5 0.75
SX6 0.98
SX7 1.10
Pump Gearbox High quality grey cast iron
Pumphead Product wetted components in 316L
Product Wetted Elastomers* EPDM, MVQ, FPM
Mechanical Seals** Carbon/Stainless Steel

*Product wetted elastomers are FDA conforming. All media contacting elastomers are controlled compression joints, the latest technology where static and dynamic elastomer seals are used to prevent pumped media leaking to atmosphere.

**Variations of these materials are available to suit fluid being pumped and/or application requirements. The seal seat and face material combinations are all EHEDG compliant.

  • Single or single flush/quench (steam barrier for aseptic application) R00 type mechanical seals
  • Double R00 type mechanical seal for flush.

All sealing options are fully front loading and fully interchangeable without the need for additional housings or pump component changes. Specialized seal setting of the mechanical seal is not required as the seal is dimensionally set on assembly. This feature further enhances fast and efficient on-site seal interchangeability.

  • Tri-Clamp® inlet and outlet ports standard
  • Screwed male inlet and outlet ports to DIN11851, SMS, ISS/IDF or RJT or Tri-Clamp
  • Heating/cooling jacket for Rotorcase cover
  • Electropolished product wetted components
  • Complete pump unit comprising: Pump + stainless steel baseplate + coupling with guard + geared electric motor, suitable for (or supplied with) frequency speed control or manual variable speed drive (advise motor enclosure and electrical supply)
  • Full material traceability on request to EN 10204 3.1


Alfa Laval rotary lobe pumps are conventional positive displacement pumps with rotor case, rotor case cover, rotors, rotor nuts, shafts, gearbox, shaft seals and elastomers. The pumps operate with no internal contacting parts in the pump head.

The SX can be supplied either as a bare shaft pump or mounted on a base plate complete with coupling, guard, gear motor and shroud for easy plug-and-play installation.

The standard materials of construction are 316L stainless steel for all wetted parts and painted cast iron for the gearbox. Other materials are available on request.

In addition, Alfa Laval manufactures all pump parts, including the rotor case and high-precision rotors. This facilitates maintenance and guarantees full interchangeability of spare rotor parts.

        SX Rotary lobe pump - Exploded

Operating principle

A gear train in the pump gearbox drives the rotors and provides accurate synchronization, or timing, of the rotors. The contra-rotating propulsion system has two rotors spinning in opposite directions within the pump head. Fluid is carried through the pump in the cavities formed between the dwell of the rotor and the interior of the rotor case.