The objective of this process is to remove coarse suspended solids that could deposit on process equipment creating scale and corrosion sites.

Filtration with coarse filters can typically range from less than 50 microns to 2000 microns. Filter cleaning is accomplished using automatic backwashing, and is required when the differential pressure on the unit increases to the point of maximum or the flow becomes too restricted. Many units limit backwash volume and can be cleaned on-line.