[Stan Weiss]

Originally Posted by Shiny

Tom, Kenth...

Help me with your use of the term "suction". To me, suction is a reduced pressure acting on the gas in the tank. What is the distinction you are trying to make?

Yes, it's the atmospheric pressure "pushing" the gas, but only because the pump is creating a vacuum relative to the atmospheric pressure inside the tank. If this is not suction, I'm confused..... just like sucking water through a straw from an open glass, right?

But for sure, if there was no vent, the gas would stop flowing when the pressure was reduced inside the tank to the max capability of the pump.... or until the tank fully collapsed!

The tank in my car has two vents, which I don't understand. One at the front and one in the neck at the rear. The vent in front is larger and feeds a vertical rubber hose "standpipe" with a filter as a baffle, but not otherwise protected against fuel flowing through it. Probably a few safety incidents with that deal... like those movie car wrecks that ALWAYS end in a fire or explosion.

This creates a pressure differential and just like when the piston goes down, atmospheric pressure pushes the fuel in the line or air into the cylinder.

Stan