Yes, if it is the press in brass check valve with a small hole in the bottom, you can block off various fuel passages and blow through the hole with a piece of fuel tubing. It will pass air one way and not the other. Some of the simple WT series carburetors just use capillary screens and will pass fuel or air in both directions. Every DLE or Walbro WT carb I have seen on recent engines has the brass press in check valve. There was a procedure at the Walbro website but I’m sorry I no longer have a link.

Some of these check valves have a rubber disc in them that can be destroyed by certain types of carb cleaners and solvents.

Do you suspect yours is bad? Unless acted on by outside forces, they rarely go bad. Damages check valves can be replaced by pressing a new one in place of the old one.

Additional thought, Walbro carbs that have accelerator pumps also use a check valve for that pump. Not sure if you were referring to that one or not.