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Judo backwash protective filters

We are an authorized representative of Judo backwash protective filters manufactured by German Judo Wasseraufbereitung GmbH. Judo filters remove solid impurities which disturb the operation of water and glycol systems from water and heat transfer fluids.

Our range of Judo filters includes both hot and cold water applications.  They are either manually or automatically operated.

Selection and sizing criteria

  • temperature of water or heat transfer liquid
  • flow rate (m3/h) of water or heat transfer liquid
  • pipe connection
  • desired filtration result (mesh size)

Operating principle

The operation of Judo filters is based on a built-in filter screen and backwashing.  During backwashing the flow direction of water is reversed and the filter screen is cleaned.

  1. Water flows from outside the filter inwards through the fine filter (filter screen).   Filtered impurities are retained by the filter screen and in cold water models visible through the transparent filter hood (sight glass).
  2. A dirty filter is cleaned by means of backwashing. During backwashing the flow direction of water is reversed i.e. water flows from inside the filter outwards.
  3. Impurities retained by the filter screen are flushed into the sewer system and the sight glass is cleaned.

Judo filters removes impurities which are larger than the mesh size of the filter screen. The filter can be equipped with a standard filter screen (0.1 mm = 100 microns) or with a special filter screen (0.03–1.0 mm = 30–1,000 microns) depending on the filtration needs.


Manual Judo filters are backwashed at full pressure by turning the hand wheel. Automatic Judo filters are backwashed on the basis of a time control (AT models) or a differential pressure control (ATP models) system.


Judo filters are quick and easy to install. In general they are installed in a horizontal lines. Filters equipped with a built-in rotary flange can also be installed in vertical lines.

Manual filters do not require any electric power. However, the power supply of automatic filters must be in the vicinity of the filter.

The filter can be installed in two ways:

  1. installation in the main flow (with a bypass if required).
  2. installation in the secondary flow (with a circulating water pump).

Only authorized persons (e.g. HVAC companies) are allowed to install Judo filters.  The filters are installed according to filter-specific installation instructions which include blasting diagrams and lists of spare parts.


Judo filters should be serviced annually. It is important to check the condition of wearing parts and replace them, if necessary.  

Judo filters improve the performance of the system and pay themselves back very quickly.