Every process is unique – that’s why we offer several backwashing/tubular systems in several configurations.
The simple, space-saving design of the AFR-Series – with only a single moving part – is ideal for the most demanding applications. The unit features a circular configuration of up to 8 tubes surrounding a central cleaning valve. During backwash, a diverter inside the cleaning valve rotates to the tube to be cleaned. This closes the tube to the incoming process liquid and opens it to the atmosphere (via the drain line). The result causes outlet process liquid to flow in reverse through the element, cleaning it of contaminants and expelling them through the drain.
AFR-Series – powerful performance in a compact footprint
The revolutionary Ronningen-Petter AFR-Series can replace an 8-station multiplex tubular system with a single unit in only a one-square-meter footprint. The simplicity of the AFR-Series design also helps to reduce overall system investment demands. Single systems can handle flow rates up to 2,000 gpm (454 m3/hr) and multiple units can be combined when higher flow rates are necessary.
Additional Choices of Media Material Configuration
ACCUFLUX® – seven-tube or fifteen-tube media configuration more than doubles surface area, compared to single-element filters of the same size
TRI-CLUSTER® – three-tube 1 1/2″ diameter media for 40 percent greater surface area than single element designs, with an economical initial investment
Cake Formation Increases Operational Efficiency
While the filtration media provides some of the filtration action, collected contaminants actually further increase efficiency. We call this phenomenon “cake formation.” The collected solids (or “cake”) trap additional contaminants. The key to making this principle work is timely cleaning – too soon and you lose the benefit, too late and the system flow becomes hindered.
Ronningen-Petter systems come factory pre-set to backwash when the differential pressure from inlet to outlet reaches 15 psi (1 bar) – typically the optimum time to initiate backwashing, although this is adjustable.

