Alfa Laval OS Twin Screw Pump

Designed for process flexibility, the Alfa Laval OS Twin Screw Pump is built on a robust, reliable platform that meets stringent hygienic standards. It is capable of handling both product transfer and Cleaning-in-Place (CIP). Its low pulsation characteristics and excellent solids handling capability reduce the risk of product damage, thereby improving product quality. Maintenance is simplified and process uptime increased.

  • Greater process flexibility
  • Ease of service, increased process uptime
  • Robust reliable design, reducing cost of ownership and increasing process uptime
  • Improved product quality
  • Exceptional hygiene and cleanability

Designed for handling sensitive, abrasive and high and low viscosity fluids, the Alfa Laval OS Twin Screw Pump is ideal for use in hygienic applications. Its quiet, virtually pulse-free, smooth and gentle operation makes the pump an excellent choice for handling sensitive products.


  • OS 22
  • OS 24
  • OS 26
  • OS 32
  • OS 34
  • OS 36
  • OS 42
  • OS 44
  • OS 46

Nine pumps sizes – OS22, OS24, OS26, OS32, OS34, OS36, OS42, OS44 and OS46 – handle flow rates ranging from 0.5 to 134.3 m3/h, pressures of up to 16 bar, and solid sizes up to 43 mm.


The Alfa Laval OS Twin Screw pump range is able to pump both process media and CIP supply with just one pump. The Alfa Laval OS range conforms to the 3-A standard and is EHEDG certified. Consequently, it is designed for use in applications within the Dairy, Beverage and Food industries where cleanability is paramount.

With a front loading cartridge shaft seal, a rigid stainless steel gearbox with timing gears located between bearings, providing balanced loading of the shaft assembly and an oil chamber design with enhanced lubrication to the bearings and gears the Alfa Laval OS Twin Screw pump is designed for optimal reliability and quick and easy maintenance. The Alfa Laval OS Twin Screw pump is available in nine models based on three frame sizes. Each frame size is available with three different screw profiles for varying pressure, flow and solids handling capabilities.

Process Flexibility
  • Easily handle process media of varying viscosities.
  • Superior suction performance with excellent lift capability.
  • Smooth and gentle in operation with low pulsation characteristic and excellent solids handling capability.
Operating principle

The Alfa Laval OS Twin Screw Pump is a positive displacement pump. As the pump rotates, the intermeshing of the two contra-rotating screws, along with the pump housing, form volumetric chambers. These chambers fill with the pumped fluid and move it axially from the suction side of the pump to the higher pressure discharge side of the pump.

Service & Reliability

Quick, easy seal replacement with the pump in place is made possible, thanks to a cartridge seal with a truly front-loading, self-setting design. This maximizes process uptime and minimizes maintenance costs. An optional seal service kit program adds maintenance flexibility and cuts operating costs.

A sturdy, all stainless steel gearbox with timing gears located between bearings, provides an optimised bearing span giving balanced loading of the shaft assembly, reducing vibration and noise, increasing component life and reliability. Oil chamber design provides for enhanced bearing and gear lubrication, minimising gearbox running temperature, increasing bearing life.

Easy access to timing gears whilst pump is in position, simplifies process of screw retiming without the need to drain gearbox oil or remove coupling and motor.

Operational Safety

A clean, external stainless steel finish with profiled elastomers and mechanical seals fully surrounded by product. Designed for maximum cleanability utilising FDA conforming materials, the pump is both EHEDG and 3-A certified.

The combination of optimized gearbox design and excellent hydraulic performance provides for quiet pump operation reducing noise emissions to a minimum. Furthermore, running temperature is minimized, increasing workplace safety. An optional ATEX version allows use in hazardous zones

ModelOS 22OS 24OS 26OS 32OS 34OS 36OS 42OS 44OS 46
Max Flow80 gpm107 gpm161 gpm153 gpm205 gpm308 gpm294 gpm394 gpm591 gpm
Max Differential Pressure232 psi174 psi116 psi232 psi174 psi116 psi232 psi174 psi116 psi
Max Speed (Process)2500 rpm2500 rpm2500 rpm2200 rpm2200 rpm
2200 rpm1800 rpm1800 rpm1800 rpm
Max Speed (CIP)3300 rpm3300 rpm3300 rpm3000 rpm3000 rpm3000 rpm2800 rpm2800 rpm2800 rpm
Max Particle Size0.47 in0.63 in0.94 in0.63 in0.83 in1.26 in0.83 in1.14 in1.69 in
Max Temp (Process)212° F212° F212° F212° F212° F212° F212° F212° F212° F
Max Temp (CIP/SIP)302° F302° F302° F302° F302° F302° F302° F302° F302° F

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