SpudFiles

I would use one of JSR's ideas in this case. Remove the spring from a schrader valve, then solder it into a 3/4 pipe nipple or something. (hint: don't heat it up and solder when the valve part is in it. Screw it in afterward)

Or just use a presta valve and you don't even have to take the spring out. I think it might even have higher flow then a schrader valve.