The Fisher NotchFlo DST valve for dirty service is available in a Class 600 rating, in 1, 2, 3 and 4-in. body sizes, and in carbon steel, chrome moly and stainless steel. NACE materials are available for corrosive applications. Its trim is pressure-balanced for smooth operation and reduced actuator size. The valve plug has a large-diameter stem and added rigidity against high-pressure conditions.