Vacuum Breaker

I need to drain my pressure tank. There is a Watts 8A Vacuum Breaker on the end of the drain valve. I have remove the Well motor breaker and drained the water from the house, pressure gauge reads 0. How do I drain the water from the pressure tank with the Vacuum breaker on it? Im pretty clueless about vacuum breakers, but the water doesn't seem to be flowing out and what Ive been able to figure out about the Watts 8A is 1) It is non-removable and 2) I must pull the leaver in the middle of body to drain it. Am I missing something?

Maybe you can unscrew it. That would drain the tank as long as your letting air back in higher than where your draining it.

bob...

There might be some fittings that thread onto the 8A that would hold open the drain lever. Is this tank indoors? All else failing, if this is a boiler drain, the whole thing could be unthreaded.