4" RIV Cast Iron Knife Gate Valve Unidirectional Double Acting Pneumatic Actuator AGRI Standard and PN10 with Position Sensor. RIV122To suit PN10 and AGRI Standard Square Flanges, 4 Hole, Cast Iron Body, Stainless Steel Blade, NBR Gaskets, Fully Enclosed for Safety, with Position Indicator, Double Acting Pneumatic Actuator Operation, with Position Sensor Rated PN10, Temperature 20C to 120C. A cast iron knife gate valve with a unidirectional double acting pneumatic actuator, AGRI standard, PN10, and a position sensor is a robust and reliable solution for controlling the flow of