vacuum tank shutoff

Unknown

Does anyone else have a vacuum tank with a combination shutoff

valve/drain at the bottom of the tank? With mine, a quarter of a turn

activates the drain and a half turn opens the line from the tank to

the carburetor. As far as I can tell it's original but I haven't seen

many like it. The value of the system is that every time you open the

valve,a small amount of whatever is in the bottom of the vacuum tank

drains out(keep a rag under the petcock while turning the gas on).Most

of the vacuum tanks I see have a separate petcock for draining the

tank. Zeke