this is what I did: I attached a hose to an empty plastic bottle, sealed it with plastic paste and put a cork in it. When i turned the water on the pressure started builiding up. What I noticed was that when it reaches about 2 bar it gets a lot hotter. I don't know why, do you? When the cork finally shoots out at about 2.5 - 3 bar , there is this grey smoke coming out of my bottle and it smells a little bit like chlorine gas, what is this smoke and where does it come from? you can watch a QuickTime movie http://users.pandora.be/k-a-d/P1010016.MOV"