Cellar Archives - valve problem

[Maexxnus]

Hello. I'm at the Cellar Archives, and I got past the first metal gate, so I'm in the big room full of water that I need to cross over to the other side to open yet another metal gate (which is in the middle of the wall to the left, when you enter the room), while avoiding the unseen horrors in the water. This second gate is opened by a valve which, I'm told, turns counter-clockwise. Thing is this valve doesn't move, neither clockwise or counter-clockwise, no matter how many time I try to turn it; so you could say I'm trapped in this level. I've searched everywhere and I can't find anyone else is this situation, can anyone help me please?