8" RIV Cast Iron Knife Gate Valve Unidirectional For Lever Operation AGRI Standard and ANSI 150. RIV130Efficiently control the flow of material with the 8" RIV Cast Iron Knife Gate Valve. Designed for lever operation, this valve meets AGRI Standard and ANSI 150 specifications. Made with durable cast iron, this unidirectional valve is a reliable choice for industrial applications. To suit ANSI 150 and AGRI Standard Square Flanges 4 Hole Cast Iron Body Stainless Steel Blade NBR Gaskets Fully Enclosed for Safety, with Position Indicator For Lever