It is impossible to account for the exact amount of loss due to evaporation or vapor emission when using inventory control or reconciliation because of losses related to other factors. These factors can include one or more of the following:
Meters Not Calibrated: Meters used in the transfer of product from the tank that may not be in calibration
Spillage that might occur during the transfer of product into the tank
Leak: A leak from the tank, piping or any dispensing equipment
Losses resulting from repairs to piping can be easily calculated and adjustments should be made to the monthly inventory control log for these losses. The total combined loss day-to-day and at the end of each month should not be greater than 0.5%.
The loss will equal the amount of product required to re-fill the piping after repairs have been completed. As an example, if the piping that was repaired is 2” in diameter and 75 feet long, the volume of product required to fill that pipe will be more than 12.2 gallons. This loss should be added back into the monthly inventory control log.