Where is the spit valve on a flute?

There is no spit valve on the Alto Saxophone. There is a spit valve on most Bari Saxophones and Contrabass Saxophones. To remove spit the easiest way is to breath in with your mouth on the mouthpiece as hard as you can. This seems a little unsanitary, but it is the most efficient way, because certain times you will not have more than half a second of a break, and if you have a spittish-tone, you will want to try to get the spit out from inside your mouthpiece.