The Clear One

The Hoffmann Precoat Filter is designed for extremely fine filtration. The systems work with great success on applications that require an extremely high surface finish, yet create small amounts of stock removal (i.e. honing and super finishing) as well as EDM applications.

Systems are available with flow rates ranging from 5 GPM to 1,200 GPM and are available in manual, semi-automatic, and fully automatic versions. All automatic systems come with drying stations.

Using the principle of depth filtration, the filter plates inside the vessel are “precoated” with a filter aid such as cellulose or diatomaceous earth. The filter cake grows and compresses steadily during the filtering cycle, dropping throughput capacity and increasing the pressure in the vessel. When a maximum differential pressure is reached or a preset filtration time ends, the filter plates are cleaned and filter cake is dried.

By utilizing horizontal filter plates, the process can be interrupted at any time without disturbing the filter cake. Manual systems are available with 27 or 43 square feet filter areas, and can be customized with magnetic separators and coolers to meet your exact needs.  Look below for our precoat filters gallery.

For ultra-fine and clear filtration of fluids

For highly demanding applications

For starting off where others stop


  • Honing
  • Super finishing
  • EDM applications
  • Available in manual and automatic models
  • Provide extremely fine filtration
  • Coolers
  • Magnetic separators
Filter Type Filter Area Sq.Ft. Tank Capacity (Gallons) Flow Rate (GPM) Dimensions (W x L) Inches
ASF 35.25 27 100 20 40 x 50
ASF 80.40 43 100 40 40 x 50
ASF 35.25.2 2×27 250 20 60 x 80
ASF 80.40.2 2×43 250 40 60 x 80

Precoat Filters Gallery