ok in part 2 when the deadly gas breaks out and you get the mask what do you have to do after that? i know im annoying you all but i really want to finish this game today. thanks for your help

Where are you? Are you in the Prison in one of the torture rooms???

no sorry its part 2 im on now and ive just set off the deadly gas in the machine room and i have the valve handle but i dont know where it goes. do you know what i mean? ill be very grateful if you could tell me trying to complete it by tomorrow thats a year now ive tried lol.

ive done the prison already now im on part 2 when the plane crashes into the facility in the artic. the part im now stuck on is after steve tries to knock down the wall he hit a gas pipe with toxic gas and you have to get a valve wheel and a gas mask. i have both but dont know where the valve wheel goes or even to stop the gas can you please help?

Ok from when Steve knocks down the wall and then runs off to do something, you then need to travel to the other end of the catwalk. Enter the door there and it will take you to the metal processing room, collect all the items and then you'll need to go to the back of this room to a machine to turn the valve handle into an octa valve handle, this will allow it to fit the hole in the mining shaft..
*If you havent already checked out the hole in the mining shaft, do so NOW. before you attempt to turn the valve wheel into an octa valve handle otherwise you wont be able to get it into the right shape*
Once you've got the octa valve handle, leave the metal processing room and then leave the catwalk through the double doors, when in the Air shaft go downstairs into the Moth corridor, defeat the moths and then go into the Antarctic office. Go to the item chest and organise your inventory, making sure you have:
Gas Mask and the octa valve handle and any other supplies.
*You're about to change character so make sure whatever you give to Claire is sensible as you wont get it back until late Part 4*
Save your game.

Then go back to the Moth Corridor and try and get through the double doors without being poisoned or implanted. You'll now be in the conveyer belt room, from here save your ammo and then enter the door at the top of the little staircase. You're now back at the mining shaft, go to the hole in the pipe and use the octa valve handle to shut the gas off. Alfred will spring another ambush on you and a sequence of events will follow and then you'll be on the next objective...

Hope this helps, if you need anymore dont hesistate to ask...

EDIT: Whoops, looks like Lyn got there first , i'll leave my post up just in case theres any confusion or something.

thamk you dear ill try that now