The abrasion resistant Chemline Exner Characterized Control Valves provide extremely precise flow control of aggressive fluids. The valves’ flow characteristics (flow rate vs. stem lift) follows the theoretical curves through the entire range of opening, including extreme ends of travel. They are rated Class IV leakage, which is 0.01% of rated capacity, according to ANSI B16.104.1076. The Teflon® bellows shaft seal provides almost frictionless stem movement and provides over 10 years of maintenance-free, predictable and repeatable control of corrosive fluids These valves respond smoothly and quickly to small changes in signal. Deadband and hysteresis is negligible.