Material Selection Guide for Wedge Wire Screens

The right material determines whether a screen lasts 2 years or 25. Selection starts with the operating environment, not the budget. Stainless steel grades SS 304/304L: Baseline for most industrial filtration. Good general corrosion resistance, widely available, cost-effective. Use 304L for welded screens (low carbon prevents sensitization). Suitable for fresh water, dry screening, grain processing, neutral pH, no chloride exposure. SS 316L: Adds molybdenum for chloride resistance. Specify for wastewater, food CIP chemicals, brackish water, or any environment where 304 would pit. Cost premium: 15-25% over 304. Default choice for food, beverage, and pharmaceutical applications. Duplex 2205 (UNS S31803): Combines austenitic corrosion resistance with ferritic strength. Yield strength roughly double that of 316L. PREN 34-35 vs 24-26 for 316L. Use for moderate marine exposure, aggressive wastewater, and high-pressure applications. Super Duplex 2507 (UNS S32750): Specified for seawater service (open-ocean intakes, coastal power plants, offshore platforms), desalination pre-treatment (RO and MSF plants), and aggressive chemical processing (concentrated chlorides, acidic brine, high temperature). PREN above 40. Cost premium: 40-80% over 316L. In seawater, 304 fails in months, 316L lasts a few years, Super Duplex delivers 25+ years. High-temperature grades SS 316Ti: Titanium-stabilized to prevent carbide precipitation above 400 C. Use for flue gas filtration, catalyst support, hot oil processing. SS 321: Also titanium-stabilized, rated above 400 C. Alloy 310S: Continuous service above 1000 C, rarely needed for screening applications. Carbon and alloy steels Use when mechanical wear, impact, and abrasion are the dominant failure modes, not corrosion. S355: Standard structural steel for moderate-duty aggregate screening and construction waste. S700: High-strength low-alloy for high-impact vibrating screen decks. Hardox 400/450/500: Severe abrasion resistance in mining and quarrying where screen life is measured in tons processed rather than years. Carbon steels cost less than stainless but corrode in wet or chemical environments. Not suitable for water, food, or chemical service. Decision framework: Start with the most aggressive chemical condition the screen will see, including cleaning chemicals. Match the material to that condition. Then check whether mechanical loads require a higher-strength grade. When in doubt between two grades, choose the higher one. The cost of premature failure always exceeds the cost of the material upgrade.