COMPLIANCE INFO_2015 - 2018 - Laserfiche WebLink

Home Browse Search

Hazardous Materials Program Guidance: UST Overfill Prevention — Page 3 of 7 Component Inspection Standard [Check the tank manufacturer's calibration chart for the capacity, diameter, and volume of product with respect to product level.] Mechanical Overfill Prevention 1. Remove the drop tube from the tank. (Flapper) Valve 2. Visually inspect the valve and float mechanism for any damage or corrosion that inhibits functionality and remove any debris and foreign objects. 3. Manually move the float mechanism to ensure it moves freely. 4. With the float mechanism in the shutoff (closed) position, visually inspect the drop tube and verify that the shutoff valve is released and will move into the product flow path. 5. If possible, verify that the bypass valve in the drop tube is open and free of blockage. 6. If problems with the shutoff valve are found and defective components need repair or replacement, notify the appropriate person. 7. Using the automatic shutoff device manufacturer's suggested procedure, examine the drop tube and shutoff valve to determine if product flow will be completely shut off at 95% of tank capacity. Make any adjustments necessary to ensure that flow will be completely shut off when the tank is no more than 9S% full. 8. After inspection of the automatic shutoff device, reinstall the drop tube. Pass Criteria = Device functions as designed and complete shutoff of product flow is able to occur when the tank is no more than 95% full. Ball Float Visually verify that all tank -top fittings are leak free and vapor -tight before starting the test procedure. If any fittings are loose, the ball float valve will not restrict flow. 1. Remove the ball float valve assembly from the tank. 2. Visually inspect the ball float and cage. Remove any debris or foreign objects. 3. Check the ball for holes and cracks. It should move freely in the cage. Check for corrosion that affects the operation of the ball float. 4. Check the vent orifice in the vent -restriction pipe. It must be open and located near the top of the tank. 5. Use the ball float valve manufacturer's installation procedure to determine if vapor flow will be restricted when the tank is no more than 90% full. 6. After inspection of the ball float valve assembly, reinstall it following the manufacturer's installation instructions. Pass Criteria = Valve functions as designed, flow restriction occurs when the tank is no more than 90% full, and the tank -top fittings are vapor -tight. Overfill Alarms 1. Measure the product level in the tank riser where the ATG probe has been removed and compare [Note: The procedures in this to the console reading to confirm ATG accuracy. If the reading does not agree, contact the test are for overfill alarms that appropriate person. are an integral of a typical 2. Verify that the overfill alarm on the ATG is set to provide a warning when the tank is no more than part 90% full. Consult the tank chart for the inch -level setting for 90% tank volume. ATG that uses mognetostrictive 3. Verify on the ATG console that the overfill alarm circuit is operational. probes for fuel level 4. Activate the overfill alarm warning to verify its operation. If found defective, contact the measurements.] appropriate person. 5. Remove the ATG probe cap and disconnect the cable from the ATG. 6. Remove the ATG probe from the tank. Use care to ensure that the product float on the stem does not catch on the bottom of the riser during removal. 7. Inspect the probe. The floats must move freely on the stem without binding. 8. Reconnect the probe cable and turn on power to monitor. 9. Set the fuel float in the middle of the probe and verify that it is showing the correct inch reading on the monitoring panel. 10. Slowly move the fuel float up the probe until the overfill alarm is triggered. If the float is moved too quickly, it may not trigger the alarm. 11. Measure the distance from the bottom of the probe to the bottom of the fuel float (confirm different manufacturers point of measurement on the float) when the float first triggers the alarm. 12. On the tank chart, find the volume that corresponds to the height of the float and determine the % of tank capacity. Use this formula to determine the % of tank capacity at which the alarm was triggered: %Tank Capacity = (volume when 90% alarm triggered / total tank volume) x 100. 13. Clear the alarm condition. 14. Compare the measurements in Steps 11 and 12 to the values programmed into the console. 15. Reinstall the ATG probe. Pass Criteria = Alarms activate when the tank is no more than 90% full and fuel level on the ATG console agrees with the gauge stick reading. HMPG-025 3/7 —Rev. 09/20/18