Roberts Filter has been designing and manufacturing horizontal pressure filters since the late 1800’s. We have over 2000 pressure filter installations, some of which have been in operation for over 100 years. Horizontal pressure filters are especially well suited for the high volume flows required by large municipalities, industries, and power utilities. The unique Roberts' multi-cell backwash system offers the economy of horizontal pressure filters, without the need for backwash pumps. The largest standard units have more that 500 square feet of filtering area, and can reliably supply plants that treat from 1 to 25 million gallons per day. Roberts' horizontal multi-cell designs partition the unit to form individual filter cells. They can often be used as a cost-effective substitute to multiple vertical units.