Always size the fuel line for the full load rate of consumption, even though you may never use that much fuel, if the generator ever goes to full load and the fuel isn't available it will be an automatic shut down.
Verify the availability of fuel to assure the generator gets the what it needs and will not experience any interupption in fuel delivery due to an appliance also requiring fuel when the generator is in service.
Please consult with your fuel provider to assure proper installation of your fuel delivery system. Most installations will require a manual shutoff valve.
Generator manufactures provide an approved (UL or AGA approved) flex fuel line with your purchase to use during installation. It is important the fuel delivery system is installed with as few bends as necessary.
Always check with your local fuel provider regarding all applicable codes for your fuel supply/delivery installation.