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�. , <br />1` -� <br />���` � ��� <br />1 1= <br />Although the effectiveness of overfill prevention devices <br />can be tested by attempting to ove�ll an underground <br />storage tank (CYST) with product and determining how well <br />the device functions, this approach is not recommended. <br />Any malfunction in the overfill prevention device could <br />result in a product release that could result in a threat to <br />public health and safety and environmental damage. <br />Federal UST rules require that overfill prevention <br />equipment automatically restrict flow or alert the transfer <br />operator when the tank is no more than 90 percent full <br />or shut off flow into a tank when it is no more than <br />95 percent full. Other alternatives to prevent overfills <br />are the restriction of flow during a delivery 30 minutes <br />prior to overfilling; alerting the operator 1 minute before <br />overfilling may occur; or automatically shutting off flow <br />into a tank so that none of the fittings located on top of <br />the tank are exposed to product due to overfilling. <br />7.1..3 ®escriptlon of Inspection. After a pre- <br />liminary inspection of the automatic shutoff instal- <br />lation, the drop tube is removed from the tank. The <br />automatic shutoff is checked for proper operation, <br />and its placement is measured to verify that it is <br />properly located to completely shut off flow when <br />the tank is no more than 95 percent full. <br />7.1..4 Preparation. Refer to the tank manufac- <br />turer's calibration chart for the capacity in gal- <br />lons, the diameter and the volume of product with <br />respect to product level. <br />If the automatic shutoff device has a float that <br />extends from the drop tube in the shutoff (closed) <br />position, verify the proper orientation of the float <br />mechanism. The float mechanism should be orient- <br />edaway from any obstructions (ball float, submers- <br />ible turbine pump [STP], tank wall, tank gauge <br />probe, etc.) If the movement of the float mecha- <br />nism is restricted, it will not function as designed. <br />Use this procedure in conjunction with the manu- <br />facturer's installation and maintenance instruc- <br />tions. <br />7.1.5 Inspection Equipment. Test equipment <br />shall include: <br />The PEI Overfill, Release Detection and Release tools for removal of the drop tube; <br />Prevention Equipment Testing Committee has written tape measure; <br />the recommended practices for automatic shutoff devices <br />to reflect that the devices must be set to shut off flow tools for inspection of the automatic shutoff. <br />when the tank is no more than 95 percent full, and flow <br />restriction and overfill alarm devices must automatically i•1.6 inspection Procedure. <br />restrict flow or alert the transfer operator when the tank 1. Remove the drop tube from the tank. <br />is no more than 90 percent full. This approach reflects the �, Visually inspect the automatic shut off valve and <br />more conservative application of the rules. float mechanism for any damage or corrosion <br />7.1 Automatic Shutoff ®evices. that inhibits the functionality of the device, and <br />remove any debris and foreign objects. <br />7.1.1 General. Automatic shutoff devices, <br />sometimes called flappers or flapper valves, are 3. Manually move the float mechanism to ensure it <br />an integral part of the drop tube assembly installed moves freely. <br />within the tank fill riser. They are designed to 4. With the float mechanism in the shutoff (closed) <br />initially restrict and subsequently completely shut position, visually inspect the drop tube and <br />off flow when product has reached predetermined verify that the shutoff valve is released and will <br />levels during a delivery. Automatic shutoff valves move into the product flow path. <br />need to be properly positioned and operate freely to 5. If possible, verify that the bypass valve in the <br />control flow and prevent tank overfills, drop tube is open and free of blockage. <br />7.1.2 Purpose. The purpose of this inspection 5, If problems with the shutoff valve are found and <br />is to verify the automatic shutoff valve is installed defective components need repair or replace - <br />properly, operates as designed and is set to com- ment, notify the appropriate person. <br />pletely shut off flow when the tank is no more than <br />95 percent full. <br />E <br />E <br />E <br />