"One-way" fuel line valve..?

Carbs haven't been a production item for 40ish years, so some folks have prob never owned/driven a carbed car, or read the manual, and prob forgot what may have been passed down, so pls bear with me.
A carb uses " venturi" vacuum, the flow of air being passed thru the carb to "suck" fuel into the carb throats.
It also has a little "squirter" (accelerator pump) that give a shot of raw fuel into the throat of the carb to give spark something to fire before venturi can suck any fuel. (other reasons too) .

To start an overnight cold engine, and normal daily driver, I was taught, and have always given the pedal 2 small pumps to set the choke, and that also shoots a coupla short shots of raw fuel for the spark plugs to fire, - otherwise cranking will be required to suck fuel by venturi into the carb throat.
The closing of the choke (if equiped) helps create the "low pressure" nec to suck, but the squirts of raw fuel short-cut the wait.
Fuel injection by itself uses a pressurized system to supply that squirt electronically every time the spark plugs fires.
The shots if raw fuel also help on a hot engine, not full depressions of the pedal, just a coupla taps, not to set choke, as it will not close hot, but to give the plugs something to fire.
That's Carbs .
Long parked cars require a little patience as described above, crank, crank, crank, not nec. (Post #20)

Good luck.