The Alfa Laval Filter (ALF) constitutes of a range of automatically selfcleaning filters/strainers, used mainly to protect heat exchangers from clogging, fouling and corrosion in various industries where cooling systems use low-quality water. ALF removes debris and marine life, reducing the risk of unplanned downtime and prolonging heat exchanger service intervals.


ALF is a pressure filter designed to maintain the thermal performance of plate heat exchangers and tubular condensers by making sure there is no debris or other undesirable materials in the water used in secondary cooling systems, via a highly effective automatic flushing set-up. Secondary cooling systems that use inexpensive, low-grade water have become widely accepted in industry, on ships and offshore installations, petrochemical plants and refineries, in power plants and in district heating and cooling systems. However, such water often contains undesirable particles, organisms and debris that can foul and clog the plate heat exchangers or tubular condensers used in such cooling set-ups. 

Increase efficiency - protecting against clogging & fouling

Fouling, clogging and corrosion can have serious effects, reducing the efficiency of heat transfer and limiting the speed at which water can flow through the heat exchanger. This results in conditions in which biological growths can flourish, and surface fouling caused by diminished flow velocities.

The Alfa Laval Filter (ALF) is a supremely cost-effective way to avoid all these problems and ensure a reliable supply of clean cooling water. The system provides the major advantage of automatic flushing carried out at regular intervals, without interrupting the filtering process or disturbing cooling operations in any way. This provides crucial peace of mind for those responsible for process equipment downstream from the ALF installation.

Reduce energy costs

The ALF also provides high filtering capacity with a low pressure drop, which cuts back on energy costs. By also minimizing the pressure drop across both plate heat exchanger and filter, an ALF installation helps reduce the overall costs of an effective cooling package. Because there are so few moving parts, maintenance costs are also low.

The ALF pressure filter has a casing made of stainless steel (ALF-S model), fibreglass-reinforced polyester (ALF-P) or rubber-lined carbon steel (ALF-R and ALF-B), and an internal cylindrical filter basket made of stainless steel. A range of different material specifications and mesh sizes are available.

ALF-B is a standardized model aimed at tasks where special options are not required. Just as the other models it offers reliable protection for your heat exchangers and fully automatic operation (backflushing).

The ALF design has the inlet directly in line with the filter and the outlet at a 90º angle. This ensures easy access to the filter basket without removing the connections, and makes it ideal for installation on any 90º pipe bend close to the equipment to be protected.


  • Heat exchangers are protected from debris and marine life, which increases cooling system uptime and lowers maintenance costs
  • Backflushing is performed automatically and does not interrupt the filtering process
  • Easy installation and maintenance
  • Proven, reliable technology
  • Full support from Alfa Laval Service throughout the entire life cycle of the equipment

More about closed loop cooling

Come funziona:

ALF is designed to maintain the thermal performance of plate heat exchangers and tubular condensers by making sure there is no debris or other undesirable materials in the secondary cooling systems. It works using highly effective automatic flushing set-up that can function automatically at predetermined intervals, or manually by pushing a button on the control panel.