Fuel pump running?

[newtotoy]

2012 4 cyl
I've only had this truck for a month and it's my first Toyota. Twice now I've heard what sounds like an electric fuel pump (very) quietly running (around the tank area) with the truck off, key out, and was parked for at least an hour.
Is there a check valve of some sort in the fuel system that might be leaking past sending a signal to the pump to keep running? Normal?

 

[doug]

Yes, it is normal. even the gen 2's did it. I think they like to keep the tank pressurized, or something like that.

 

[newtotoy]

Thanks Doug.

 

[doug]

Thanks Doug.

No problem, of course when I say tank, I mean the fuel system its self, because as we all know, the tank itself is vented.