Most bar screen and raking systems are expected to last 10 to 25 years before needing replacement. As components wear, and steel corrodes, wastewater treatment plants (WWTPs) have to choose between replacing parts and specifying a new system. Both situations can present a serious challenge. For example, replacing parts may seem more cost-effective in the short run; however, over time more and more components will inevitably fail or underperform, and the cost of parts, labor, and downtime will mount.
Source: WaterOnline.com