Too Much Coffee

I have a 9 cup pot at work and it leaks a little most of the time we use it. Why? I screw it on tightly, I don't overfill it or tamp, set the stove on medium to hot (and turn it down as soon as the coffee comes). What am I doing wrong?

The big size of Moka pots do have problems as opposed to the smaller ones. To me it seems they have a very quick action compared to the smaller ones and the coffee they make is inferior. My theory, for what it's worth, is that the pressure required in order to force the water the height of the upper chamber is too much, giving problems.
I take it the gasket is ok?

What's a gasket?

I agree that the bigger pots are not as good as the small ones. My one-cup moka pot is by far the best I own and if I'm the only one drinking the coffee that's the one I use.

The "gasket" is the rubber ring that provides the seal between the lower and the bottom part.
It becomes hard and loses its elasticity in time and especially if you're in the habit of screwing the two halves together too tightly.

Thanks for the warning tip. No need to prove my manlyness when screwing the parts together, huh?