Here's a quick model of the valve as I'm working on it now.
The chamber would be to the left, the barrel to the lower right, and the upper right would be plugged, with a tap to fill the chamber, which would also act as an air pilot to open the valve. The open end of the slanted bore would be plugged with a solid plug after connecting the two other bores.
Any co-axial valve that I could think of was too restricting for efficient air flow. And the electric lawn sprinkler valve, besides being inefficient for air was way too big. The big eureka moment came when I figured out to have the air from the chamber push the valve core open and then "side-step" it.
The chamber would be to the left, the barrel to the lower right, and the upper right would be plugged, with a tap to fill the chamber, which would also act as an air pilot to open the valve. The open end of the slanted bore would be plugged with a solid plug after connecting the two other bores.
Any co-axial valve that I could think of was too restricting for efficient air flow. And the electric lawn sprinkler valve, besides being inefficient for air was way too big. The big eureka moment came when I figured out to have the air from the chamber push the valve core open and then "side-step" it.