Mystery Part on Predator Engine Fuel Tank Question

[PGB1]

Hi All!
I have another post about finding the manual for this Predator 212 & StarTech was kind enough to find me the parts list. It's a Loncin G210FA in real life. (Thanks to StarTech's information)
Instead of cluttering that post, I thought it forum etiquette to ask this question separately.

On top of the fuel tank is a disc with a piece of fuel line leading to a chamber inside of the carburetor cover. It is the same chamber to which the valve cover breather tube goes. The parts list calls it a "Fuel Valve".
If I blow in the tube or suck on it, air goes both directions. But, if I tip the tank, air stops, telling me that there is a float inside.

Do you know what this item does for a living? Is it an emissions device, or perhaps something to dump fuel if the engine is over filled?

Thanks For Helping Me Learn This Engine!
Paul

PS: I'll know it well by the time I get it running! In the carburetor cover, the air cleaner, the valve cover were packed with zillions of ants and ant larvae. Looking in the spark plug hole shows a few ants on top of the piston. First job will be clean up.

 

[StarTech]

Rollover valve.

Its primary job is to allow air/vapors to vent normally during everyday use and refueling, but it instantly closes if the engine rolls over or tilts at a dangerous angle, sealing the fuel inside the tank to prevent dangerous leaks and fires.

 

[PGB1]

Thanks once again Star Tech. you surely know this engine well! (For others scratching their heads, Star Tech was kind enough to help me a lot in another post.)
Paul

 

[Auto Doc's]

It's something else to break and only comes with a new tank. It is a "roll over" valve in the event that the engine is tipped to an extreme angle.

 

[PGB1]

It's something else to break and only comes with a new tank. It is a "roll over" valve in the event that the engine is tipped to an extreme angle.

My temptation, since snaking in a new hose in (old one rotted) involves removing the carburetor and housing surrounding it, was to leave the tank valve open to the air & plug the carburetor end. I empty gas tanks after using engines, so fumes should be minimal. (Or if the gas cap is vented, I'll plug the valve. )

But, knowing me, I'll replace that pesky hose because it "just ain't right".

 

[Auto Doc's]

The fuel caps on newer equipment are not vented, which is another reason for the valve with the hose running to the air cleaner housing. With the engine running it pulls off fuel vapors created by the engine vibrating the fuel in the tank.

 

[StarTech]

PN 172830008-T040 appears to be NLA but PN 172830008-0001 is available may very well be the same part. Can't tell from the only image available if it come with the grommet or not.

 

[PGB1]

The fuel caps on newer equipment are not vented, which is another reason for the valve with the hose running to the air cleaner housing. With the engine running it pulls off fuel vapors created by the engine vibrating the fuel in the tank.

Thank You for the explanation of the need for this valve.
Paul

 

[PGB1]

PN 172830008-T040 appears to be NLA but PN 172830008-0001 is available may very well be the same part. Can't tell from the only image available if it come with the grommet or not.

Thanks for the part numbers. I appreciate your help.
Paul