Screening equipment is an important preliminary stage in the total water treatment process, as it removes from the liquid stream the bulk of the non biodegradable matter, such as plastics, woven materials, pieces of wood and metallic items that can cause blockages and impact damage to mechanical equipment.

Fine screening also removes some biodegradable solids, but these only form less than 1% of the biological load, therefore their loss is not detrimental to the treatment process.

Heavy duty back raked screens: These screensare specifically designed for heavy duty removal of weed and debris in large scale water handling facilities. The raking tines plunge into the weed or debris mass at the base of the intake channel. They do not have to descend through the contaminated water as is the case with for front-raked machines. All working parts are protected behind the static grid and consequently function on the clean side of the bar screen.

All debris, rags or weeds are removed from the bar screen in the firstraking motion.