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J <br /> VALVE OPERATION <br /> The Franklin Fueling Systems (FFS) Defender Series° Overfill Prevention Valve (OPV) is designed <br /> with a primary shutoff that activates between 85 and 92% of tank volume, depending on the <br /> tank diameter. When the primary shut-off is actuated, the flow through the OPV is limited to less <br /> than 8 GPM (30 LPM). A secondary, positive shutoff happens at 95%tank volume if you continue <br /> filling. After primary shutoff, you can still drain the delivery hose, but you must be extremely <br /> careful and follow these steps: <br /> 1. Close the truck bottom loading valve. <br /> 2. Wait 5 minutes. <br /> 3. Partially open the coupler between the delivery hose and the bottom loading valve and <br /> allow the hose to drain. <br /> NOTE: Shutoff points are affected by the specific gravity of the stored liquids. These instructions <br /> are based on the average performance of all products. The OPV was designed to be only an <br /> emergency overfill prevention device. <br /> NOTE: Determine if the underground storage tank has a ball float vent valve. If it does, make sure <br /> the nipple portion does not extend more than 3" (76.2mm) into the tank. <br /> TANK SIZE AND INSTALLATION OF OVERFILL PREVENTION DEVICES <br /> In a two-stage, mechanical Overfill Prevention Valve (OPV), primary closure of the device <br /> significantly restricts the flow of fuel into the tank. After primary shut-off occurs, the delivery <br /> hose can be drained slowly 3-5 GPM (11-18 LPM) until secondary or "positive" shut-off occurs. <br /> Under current EPA regulations and industry standards, secondary shut-off is typically set at 95% <br /> of tank volume; however, other local regulations may prescribe other values. <br /> Mechanical OPVs use a float(s) to trigger shut-off, or closure, of the device and restrict flow to <br /> the storage tank. The shut-off level of the secondary ("positive") closure can be set based on <br /> the height of installation in the tank. The height of this installation typically is correlated with a <br /> volume percentage such as 95%.The level of the primary shut-off point will fluctuate to some <br /> degree based variables such as the: <br /> • Size and shape of the tank. (See the images below.) <br /> • Specific gravity of the stored liquid: <br /> The offset picture is based on a specific gravity of 0.75 for gasoline and 0.85 for diesel. A <br /> lower specific gravity will need more fluid to create equivalent buoyancy, which equates to a <br /> higher shutoff level (and vice-versa). <br /> • Flow rate during delivery. <br /> The offset is based off data from our production flow test apparatus, which runs at 370 <br /> gpm. A lower flowrate causes less buoyancy force needed to activate the primary, which <br /> equates to a lower shutoff level. <br /> The most influential of these variables is the size and shape of the tank volume, as illustrated <br /> below. Always use a calibrated tank chart in combination with the manufacturer's instructions for <br /> best results. <br /> 3 <br />