Remote Controlled Door in Chemical Lab

[Janakev]

Ah, this was a good one.

Spoiler below!

Notice that the door is shut due to the nearby gas leak. Around the corner from the pipes there should be some debris and a piece of piping. Grab a lump of the concrete with the brick in it and hit the piece of piping that's leaking gas. Perpendicular to that there should be piping with a protective cap on it. Hit the cap.
Now, go back and get the piece of piping. Bring it back to the pipe you've just broken and use it to divert the pipe into the one which you just broke the cap off.