Abstract: The gas valve assembly includes a housing with a bore and a main valve body and a main valve stem mounted therein. The valve body has a fluid passage fluidly connecting the inlet and one of a housing and valve body outlet with the valve stem mounting a valve seat and being movable for blocking fluid flow through the passage. In two embodiments, the housing is threadable to the neck portion of a vessel for the inlet opening to the vessel interior and the main valve body mounts a manual operated shut off valve extending within the valve body to selectively block fluid flow through the passage and an excess flow valve to block fluid flow through the passage when the flow to the outlet is greater than desired. The last two mentioned valves include a common piston in the fluid passage.