This 48" knife gate valve is made of high strength 2205 Duplex Steel instead of standard stainless steel for processing more corrosive and abrasive materials. Ferritic/austenitic stainless steel material used in the valve make it 50% stronger than austenitic stainless steel valves as well as more corrosion resistant in many applications. Valve has a face-to-face dimension of 6" and is designed for assembly without welding. Stainless Valve Co. 4811 Persimmon Ct. Monroe, NC, 28110