THIS IS REALLY OUTDATED AND INCOMPLETE, PLEASE REFER TO THIS GUIDE
viewtopic.php?f=15&t=4941
This guide (once completed) will cover most of the basics of atmospherics: gear, setting up atmos, firefighting, defending atmos, repairing breaches, crowd control and correct use of the fireaxe. I won't cover anything more advanced as most of that is up to personal preference.
Setting up atmos
This, right here is pretty your entire job. (Not your most important job, that's keep the fireaxe safe and use it properly) Now, most techs are sadly idiots that have no idea how to even setup the filters, (training cuts) so don't be surprised if you get yelled at or half your work gets changed. Just talk to the CE. (Or show em correct use of the fireaxe.)
Atmos is much, much simpler then it looks. Most of it can simply be ignored.
Dirty air comes in the red waste loop. That enters the green filtering loop where each type of gas is sorted into a tank. N2 and O2 are then pumped into the air tank by the first stage of the cyan distro loop. Then the air tank is pumped into the second stage of the blue distro loop where it is sent out around the station.
Simple enough?
Now, to setup atmos right you have to change a few things so gas is pumped round and filtered quickly. The faster dirty air from a plasma fire gets to atmos and the faster clean air refills a breached room the better.
First, go round and change each filter to 4500. Every single one. Doing that will get the gas going into each tank much faster. Otherwise the waste loop would never clear.
Once you have finished with the filters you need to fix a major atmos problem: hot gas (such as from plasma fires) expands and that clogs the loop. How you fix that is simple: cool it down. And the four coolers will do just that. Go cooler by cooler and turn them. Leave them at the temp they are already set at. Once every cooler is on, you then need to send waste gas TO the coolers.
First, find the two pumps in the picture. Replace those with volume pumps. Make sure they are going the right way. (The red line points to where the gas will go)
Then, follow the above picture. Turn the digital valve to point towards the coolers. Turn both volume pumps you replaced on. Find the manual valve that leads to the coolers and turn it on. Check everything. Then check it again.
If you setup it right the coolers should be cooling any gas that comes through the waste loop.
See that multitool on the table? And the volume pump on the cyan pipe above it? That starts as a pump. Replace that with a volume pump as seen in the picture.
Now, a major problem with the default atmos setup is that it is rather easy to sabotage. But it is also rather easy to fix. See the slightly discolored yellow pipes in the above picture? Those normally have two valves connecting up three tanks holding some very dangerous gases. Just simply remove the T-junction and the valves, replace the missing pipes and boom, atmos is now damn hard to screw up.
There, atmos is setup. While it isn't the best possible setup it is the best you can do without changing a huge amount of the station. (To my knowledge, if you have any ways I can improve this please comment)
Now, this guide is still rather unfinished and I will add many more sections. If you have any suggestions please let me know.