Suspended solids and turbidity are among the most common water quality problems encountered across water treatment, industrial process water, and wastewater applications. Pressure sand filters address these by passing water through a bed of graded filtration media under pressure, capturing suspended particles as the water moves through the media bed and producing a clarified filtrate.

The pressure operation distinguishes these filters from gravity filters. By applying pressure, higher filtration rates can be achieved in a given filter area, making pressure sand filters more compact than their gravity equivalents for the same treatment throughput. This is an advantage in applications where space is limited or where a small treatment footprint is important.

Multi-layer media configurations use a combination of media types, typically anthracite over sand over gravel support, each selected for particle size and density. The coarser upper layer captures larger particles while the finer lower layers remove progressively smaller suspended solids. This staged capture mechanism distributes the solids load through the depth of the media bed, extending filter run times and improving overall filtration efficiency.

Backwashing is used to clean the filter when the media bed becomes loaded with captured solids and the differential pressure across the filter increases to the point where flow rate begins to decline. Backwash involves reversing flow through the media bed at sufficient velocity to fluidise the media and release captured solids, which are then flushed to drain.

Used in water treatment plants, cooling tower sidestream filtration, industrial process water systems, and wastewater polishing applications, pressure sand filters are a standard and reliable component in the treatment toolkit.