8" RIV Cast Iron Knife Gate Valve Unidirectional Handwheel Operated AGRI Standard and ANSI 150. RIV131The 8" RIV Cast Iron Knife Gate Valve is the perfect solution for reliable and efficient fluid control. Featuring unidirectional operation and a handwheel for easy use, this valve meets both AGRI Standard and ANSI 150 requirements. Durable and versatile, it's a must have for any industrial setting. 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