In the SYPHON FILTER OMEGA STRAIN game. on the lorelei rig?

i am at a lost in this level, i cant find a way to reach level 2 to get the uniform. how do i get to this level? also once i make it to level 12, after the explosion goes off and the 3 minute countdown begins, i cant find the shut off valve to save the worker. where is the shut off valve located.?