The Defender Series™ overfill prevention valve (OPV) is a self-contained two-stage positive shut-off valve that prevents the overfill of an underground storage tank (UST) during a gravity-fed product delivery. The Defender Series™ OPV employs a revolutionary magnetically-coupled actuator system to provide positive shut-off. This unique method of shut-off eliminates any penetrations in the valve, making it both vapor- and leak-tight. The Defender Series™ OPV provides safe, rapid, and reliable fuel drops for the broadest range of fuel
applications and environmental conditions. Simple to install, service, and test remotely, the Defender Series™ OPV is the industry's most versatile overfill prevention valve. Defender Series™ overfill prevention valve with 5' (1524mm) top drop tube, 8' (2438mm) bottom drop tube.