Equipment compatible with E10, E20, E85, E100 (from the Petroleum Equipment Institute - alternative fuels compatibility guide)
In general, tanks, pumps, lines, and dispensers that are currently used for gasoline can be used for ethanol blends without any modification. As a precaution, some marketers will change pump filters more frequently when beginning sale of ethanol blends, but this is rarely necessary unless tanks or lines contain rust, varnish, gums, or large amounts of sludge. In any of those cases, the sources of those problems must be addressed before adding ethanol blended fuel to the storage tank.
The major manufacturers of steel and fiberglass tanks have had the same warranties for gasoline and ethanol blends since 1978. Polyester or epoxy coatings installed prior to 1980 are not suitable for ethanol blends. If you have any question about the age and material used to line a tank, contact the manufacturer of the coating before storing ethanol blends in that tank.
They are lists of equipment that is compatible with E10, E20, E85, and E100. The Petroleum Equipment Institute hosts the site, and manufacturers are encouraged to list their products there.
Care must be taken to eliminate water and remedy any causes of water buildup in tanks that will be used for ethanol blended gasoline. In addition to regular leak detection, be sure to check gaskets, fill caps, and tank lids, and remind transport drivers of the importance of replacing all of them correctly when making fuel deliveries. Water is the worst enemy of ethanol, and relatively small amounts of it in tanks can cause phase separation.
The preferred method for switching a tank from storage of straight gasoline to an ethanol blend is to empty the tank completely and pump the water at the bottom until the tank is completely empty. The tank should be filled as close to capacity as possible, to minimize the effect of any small amounts of water that may remain following cleaning. In areas where MTBE is in use, and/or where RVP restrictions are a concern, this is the only acceptable method for switching products.
An optional method would be to blend existing volumes of straight unleaded gasoline with fuel containing sufficient "extra" ethanol to bring the entire mixture to the proper percentage. For example, if a 10,000 gallon tank contains 2700 gallons of straight unleaded gasoline, 300 gallons of ethanol can be added to a delivery containing 10% ethanol to bring the entire tank's contents to 10% ethanol. Again, care should be taken to remove any water from the tank bottoms, and the tank should be filled as close to capacity as possible, to minimize the effect of any small amounts of water that may remain. Given the previous scenario, a load made up of 5400 gallons of gasoline and 900 gallons of ethanol would be added to the 2700 gallons of unleaded gasoline to make 9000 gallons of E10 (8100 gallons unleaded, 900 gallons ethanol).
Using the second method, pumps must be shut down when the fuel level reaches the desired volume to assure proper blend. Close coordination with fuel suppliers should allow them to schedule delivery to minimize the amount of time the pumps need to be out of service.
Be sure to label pumps appropriately, indicating the proper octane of the blended fuel, and placing any decals required by state motor fuel regulations.