Gravity GPM for 1" pipe I am in the process of buying an 83 gal. fuel transfer tank. The tank is 48"L x 20"H x 20"W. Instead of buying pumps for filling up my 5 gallon gas tanks I was thinking about using gravity flow. The builder can install a 1" fitting at the base of the tank with a 1" hose. The tank is going inside an enclosed trailer so I am limited on how high I can build the tank. I can build the tank 2 feet off of the floor of the trailer plus the 9 inch clearance from the floor of the trailer to the ground level. I will be using a ball valve to turn it off and on. What is the gallons per minute when in use. I understand that the GPM will vary depending on the amount of gallons in the tank. What is the GPM at 100% capacity, 50% capacity and 25% capacity? Thanks for your time and consideration.