Welcome to Atmospherics, the place where Dreams Come True™. Or at least the place that can partially sustain the ability to dream... y'know, by allowing you to breathe and stuff. Breathing is important, and the primary function of this maze of pipes and gas is to distribute breathable air throughout the station efficiently, and to restore air to depressurized - but hopefully air-tight - rooms. Its secondary function is to process contaminant gases captured by the scrubber network and sort the gas accordingly into one of many chambers.
If you're new to all of this - or even just someone who's never really given Atmos a fair shake - then this will all look very complex and downright intimidating to look at. This mostly stems from just how much stuff can get on screen at once, but there's a few things put in place to make pipe-readability easier on the user if they just take the time to truly examine what each pipe network is meant to do. Alongside that will be this guide to help you out.
What Do These Colors Mean?
So there's a lot of pipes with a bunch of colors and they all look really important. It's true that all of the colored pipes - which represent different pipe networks - have their place in the department, but not all of them are strictly necessary to produce gas. Here's all of the important colors, though note that the colored pipes beneath the catwalks aren't to be taken into account:
Air Mix: This is the air mix loop, and these pipes are the most important: they're the ones that contain the air mix, which is combined at a mixer set to specific percentages to ensure that the gas everyone breathes is, in fact, breathable. Tampering with the mixer is ill-advised, as is modifying this network in such a way that it will not be able to reach the distribution network.
Distribution: Equally important is this blue network, offset pipes to the south alongside the scrubber pipes. This massive network of pipes is what will actually distribute the air that it receives from the air mix loop and send it all towards vents placed all around the station, ensuring every room remains at optimal pressure.
Filtering: These pipes are part of the filtering network, a pipe line connected to the scrubber network that leads to filtering devices which will filter a select gas out of the line and output it into a large storage chamber full of that same gas. If the gas type does not match then it'll continue down the line until it eventually does reach where it's meant to go. If, somehow, it reaches the end of the line and doesn't match any of the filtering criteria then it will just be output into the mix loop.
Scrubber: You'll probably notice some pipe adapters and pipes that aren't centered towards the south of Atmos proper. These pipes are part of the scrubber network and, as you can imagine, much of this network is comprised of scrubbers. The end of this line - where all of the scrubber pipe contents are pumped out towards - is the filtering line.
Mix: This line is a bit odd, but its intended function is to provide a pipe network that you can pump any of the gases in atmos into, allowing you to make custom mixes and letting you warm them up or cool them down. Using this line isn't necessary for Atmos to function, but it's good to use as a test bed of sorts if you'd like to experiment with how devices interact with pipe networks. Note that part of this network is colorless.
Misc Mix: These pipes aren't actually part of a network, they just pipe oxygen and nitrogen into a mixer which outputs into the air chamber which later outputs into the air mix line.
Waste: These are the black pipes, as few as they are, towards the southern end of Atmos proper. It's intended function is to eject undesirable gas out into space harmlessly, usually by pumping gas you don't want filtered into it from either the mix line or the filter line by way of pumps, and turning a valve open to space.
Principles and Concepts
Pressure
Delta P
watch out for that pressure differential. also 200 kpa ambient pressure blah blah
Pressure (in kPa) * Volume = Moles * 8.314 (the molar gas constant) * temperature (in Kelvin. Kelvin = Celsius + 273.15)
Gas Gas Gas
Oxygen (O2): 20 SH, 0.032 MM, oxidizer, necessary for life
Nitrogen (N2): 20 SH, 0.028 MM, inert, non-toxic
Air (Air): 79% N2 21% O2
Carbon Dioxide (CO2): 30 SH 0.044 MM, toxic in high concentrations
Nitrous Oxide (N2O): No, it's not N20, it's N2O. Jamming twenty nitrogen molecules together would be stupid. 40 SH 0.044 MM, sleep agent, oxidizer
Hydrogen (H2): 100 SH 0.002 MM, fuel, non-toxic
Phoron (PH): 200 SH 0.405 MM, fuel, toxic, contaminant
Relevant Tools
necessary stuff you'll maybe want
Impact Wrench: The impact wrench (or power drill, if you prefer) is a tool that condenses a screwdriver and wrench down into one tool. As you've probably found out by now, activating the item in hand will change its bit. For pipes you'll want a wrench bit in order to either secure or unsecure pipe sections and other devices. It cannot unwrench a pipe if its internal pressure exceeds 200 kPa over ambient pressure.
Wrench: If you're missing an impact wrench then you probably have this instead. When it comes to pipe interaction there is no difference between this tool and its powered counterpart.
Pipe Wrench: As the name might imply this tool is specialized towards dealing with pipes. The pipe wrench's biggest advantage over other wrenches is that it can unsecure a pipe at any pressure. It's also able to mangle bend or straighten simple pipe segments if they are not already secured. This comes at the price of being unable to function like a normal wrench for anything other than pipes and atmospheric devices.
Gas Analyzer: This tool is invaluable to any aspiring atmos tech. Though some may argue you should already have an innate sense of exactly what's inside a pipe via telepathy (you're the person in charge of that gas, you put it in that pipe!!!) this shouldn't stop you from deciding to use a tool like the analyzer. Once upon a time this device did pretty much nothing but now it can be used to measure the following:
It can also be used to analyzer gas on the turf you're standing in by activating it in hand.
Pipe Dispenser: Despite the fact that this object cannot be held, it is still a tool. Put simply, when secured to the floor (with a wrench) in a powered area, this device will vend pretty much anything under the pipes subheading, giving you plenty of options. Oddly enough securing this to the floor is faster than unsecuring it. The more you know.
Rapid Fabrication Device - Pipes: The handheld version of the pipe dispenser, the RFD-P is capable of... well, pretty much everything its bigger cousin can do, though with a smaller list of pipes and devices that can be created, heat exchange pipes most notably having gone missing. Activating the item in hand will bring up a list of pipes, and alt-clicking it will swap through device categories. The RPD requires matter cartridges in order to operate, but thankfully the ones that can be found in lockers are already loaded.
Файл:Multitool.pngMultitool: Perhaps an unexpected addition, but the multitool actually does have a use in the land of pipes, as niche as it is. It is used to flip which overlapping pipe network a meter observes. For instance, if one network crosses from east to west and another network crosses from south to north on the same turf, and a multitool is secured over these pipes, using a multitool on it will swap between both pipe nets. Figuring out which is which is as simple as waving your gas analyzer over a network and comparing the readings.
Pipes and Devices
Stuff can be rotated with alt click lol
Basic Pipes
Many of these pipes have distro and scrubber variants.
Straight: The most common type of pipe you will see. It goes straight from one direction to another. It holds up to 70L.
Corner: Effectively the same as the straight pipe, except it's not straight. Wow!
Manifold: A pipe with three ends on it instead of two. Holds up to 105L.
Four Way: Even better than the previous entry, this one has four ends. Whooooaaaa. Holds up to 140L.
Файл:Pipecap.pngCap: A bit that simply closes off the end of a pipe with a cap. There's no real reason to use this, especially since pipes don't leak, but it holds up to 35L regardless.
Файл:Zpipe.pngZ-Pipe: A pipe piece that connects one level to another. Holds 70L, but since you need at least two to make this work it's effectively 140L.
Universal Pipe Adapter: This special piece of work will connect different pipe types together, namely normal, distro, and scrubber pipes. This can make for some rather creative pipe setups if you don't mind a few pipes being colored red or blue. Holds up to 70L.
Файл:PipeHE.pngHeat Exchange: Special pipe designed in a way to equalize heat with the gas inside and the environment that it's in. In other words, if you pipe super cooled gas into heat exchange pipes winding around a room that's normally at room temperature, then the room will cool down and the gas will heat up. Holds up to 70L.
Файл:PipeHEJ.pngJunction: Weirdly enough, pipe adapters cannot connect heat exchangers to normal pipes, requiring the use of this special pipe. On one end goes normal pipes and on the other goes heat exchange pipes. You can figure it out.
Файл:Pipeinsulated.pngInsulated: Extremely niche pipes, these have no special use other than reinforcing pipes well beyond what's necessary. Only consists of straight pipes, meaning there's no manifolds or four-ways. Holds up to 70L.
Devices and Utilities
most powered devices use 150 watts when idle
Non-Pipe
Pipe Meter: A device that will observe whatever pipe network it is secured onto. It will tell you the temperature and pressure of the network, even from a distance, and it even gives visual indicators of the pressure! This won't replace gas analyzers, though, since it can neither determine how many moles are in a net nor can it determine what gases are in the network.
Turf Meter: The pipe meter's slightly awkward cousin, this will measure the gas on the turf that it is secured upon. It's functionally similar to its cousin.
Gas Sensor: What could be considered an advanced turf meter, minus the visual indicators. In fact, this device requires a specific console in order to see what it's reading. You'll probably see these in the large gas chambers.
Unary
Connector: Definitely one of the most important utilities in any atmos setup, this will allow you to connect any portable atmospheric device to to a pipe network with a wrench.
Heat Exchanger: Not to be confused with the heat exchange pipes seen above, this radiator is designed to face another heat exchanger in order to balance heat between two networks without actually mixing the gases together.
Gas Cooler: A large device that is capable of cooling the contents of a pipe network to near-Absolute Zero values. How fast it cools and how large its volume is depends on upgrades made to it. Holds 600L by default.
Gas Heater: A large device that is capable of heating the contents of a pipe network to rather high values. How fast it heats and how large its volume is depends on upgrades made to it. Holds 600L by default.
Air Injector: A device whose whole purpose is to pump gas (not just air, like the name implies) onto a turf, similar to a vent pump, except it's rated to pressurize up to 15000 kPa. Usually controlled from a special console. Holds 700L, allows a flow rate of up to 700L/s, rated to pressurize up to 15000 kPa, can consume up to 15 kw at max operational capacity.
Vent Pump (Unary Vent): The device that you'll probably see the most around the station, these vents are typically controlled by an air alarm to determine what pressure to target. Special versions of this vent allow it to siphon gas indiscriminately instead, a notable example being the vent pump in the SM core. Holds up to 200L, allows a flow rate of up to 200L/s, rated to pressurize to 7500 kPa, can consume up to 7.5 kw at max operational capacity.
Scrubber: Where a vent pump (usually) pumps a gas (typically air) into a room, scrubbers do the opposite, with a twist: they can be controlled by an air alarm to target and collect any type of gas and pump it into a pipe network. It can also be set to forcefully siphon gas indiscriminately, giving it a lot more power. Holds up to 200L, allows a flow rate of up to up to 200L/s, 2500L/s on siphon, rated to pressurize to 7500 kPa, can consume 7.5 kw at max operational capacity.
Cryo Cell: Maybe not immediately concerning to your average pipe enthusiast, the cryo cell is nonetheless an atmospheric utility. It's connected to a pipe network that hopefully has chilled oxygen, which can be used to put a patient in stasis and heal some of their wounds. See the guide to medicine for more info.
Binary
Pressure Regulator: Effectively 1000L, 500L/s, no power usage
Oxygen (O2): 20 SH, 0.032 MM, oxidizer, necessary for life
Nitrogen (N2): 20 SH, 0.028 MM, inert, non-toxic
Air (Air): 79% N2 21% O2
Carbon Dioxide (CO2): 30 SH 0.044 MM, toxic in high concentrations
Nitrous Oxide (N2O): No, it's not N20, it's N2O. Jamming twenty nitrogen molecules together would be stupid. 40 SH 0.044 MM, sleep agent, oxidizer
Hydrogen (H2): 100 SH 0.002 MM, fuel, non-toxic
Phoron (PH): 200 SH 0.405 MM, fuel, toxic, contaminant
Impact Wrench: The impact wrench (or power drill, if you prefer) is a tool that condenses a screwdriver and wrench down into one tool. As you've probably found out by now, activating the item in hand will change its bit. For pipes you'll want a wrench bit in order to either secure or unsecure pipe sections and other devices. It cannot unwrench a pipe if its internal pressure exceeds 200 kPa over ambient pressure.
Wrench: If you're missing an impact wrench then you probably have this instead. When it comes to pipe interaction there is no difference between this tool and its powered counterpart.
Pipe Wrench: As the name might imply this tool is specialized towards dealing with pipes. The pipe wrench's biggest advantage over other wrenches is that it can unsecure a pipe at any pressure. It's also able to 
Gas Analyzer: This tool is invaluable to any aspiring atmos tech. Though some may argue you should already have an innate sense of exactly what's inside a pipe via telepathy (you're the person in charge of that gas, you put it in that pipe!!!) this shouldn't stop you from deciding to use a tool like the analyzer. Once upon a time this device did pretty much nothing but now it can be used to measure the following:
Pipe Dispenser: Despite the fact that this object cannot be held, it is still a tool. Put simply, when secured to the floor (with a wrench) in a powered area, this device will vend pretty much anything under the pipes subheading, giving you plenty of options. Oddly enough securing this to the floor is faster than unsecuring it. The more you know.
Rapid Fabrication Device - Pipes: The handheld version of the pipe dispenser, the RFD-P is capable of... well, pretty much everything its bigger cousin can do, though with a smaller list of pipes and devices that can be created, heat exchange pipes most notably having gone missing. Activating the item in hand will bring up a list of pipes, and alt-clicking it will swap through device categories. The RPD requires matter cartridges in order to operate, but thankfully the ones that can be found in lockers are already loaded.
Straight: The most common type of pipe you will see. It goes straight from one direction to another. It holds up to 70L.
Corner: Effectively the same as the straight pipe, except it's not straight. Wow!
Manifold: A pipe with three ends on it instead of two. Holds up to 105L.
Four Way: Even better than the previous entry, this one has four ends. Whooooaaaa. Holds up to 140L.
Universal Pipe Adapter: This special piece of work will connect different pipe types together, namely normal, distro, and scrubber pipes. This can make for some rather creative pipe setups if you don't mind a few pipes being colored red or blue. Holds up to 70L.
Pipe Meter: A device that will observe whatever pipe network it is secured onto. It will tell you the temperature and pressure of the network, even from a distance, and it even gives visual indicators of the pressure! This won't replace gas analyzers, though, since it can neither determine how many moles are in a net nor can it determine what gases are in the network.
Gas Sensor: What could be considered an advanced turf meter, minus the visual indicators. In fact, this device requires a specific console in order to see what it's reading. You'll probably see these in the large gas chambers.
Connector: Definitely one of the most important utilities in any atmos setup, this will allow you to connect any portable atmospheric device to to a pipe network with a wrench.
Heat Exchanger: Not to be confused with the heat exchange pipes seen above, this radiator is designed to face another heat exchanger in order to balance heat between two networks without actually mixing the gases together.
Gas Cooler: A large device that is capable of cooling the contents of a pipe network to near-Absolute Zero values. How fast it cools and how large its volume is depends on upgrades made to it. Holds 600L by default.
Gas Heater: A large device that is capable of heating the contents of a pipe network to rather high values. How fast it heats and how large its volume is depends on upgrades made to it. Holds 600L by default.
Air Injector: A device whose whole purpose is to pump gas (not just air, like the name implies) onto a turf, similar to a vent pump, except it's rated to pressurize up to 15000 kPa. Usually controlled from a special console. Holds 700L, allows a flow rate of up to 700L/s, rated to pressurize up to 15000 kPa, can consume up to 15 kw at max operational capacity.
Vent Pump (Unary Vent): The device that you'll probably see the most around the station, these vents are typically controlled by an air alarm to determine what pressure to target. Special versions of this vent allow it to siphon gas indiscriminately instead, a notable example being the vent pump in the SM core. Holds up to 200L, allows a flow rate of up to 200L/s, rated to pressurize to 7500 kPa, can consume up to 7.5 kw at max operational capacity.
Scrubber: Where a vent pump (usually) pumps a gas (typically air) into a room, scrubbers do the opposite, with a twist: they can be controlled by an air alarm to target and collect any type of gas and pump it into a pipe network. It can also be set to forcefully siphon gas indiscriminately, giving it a lot more power. Holds up to 200L, allows a flow rate of up to up to 200L/s, 2500L/s on siphon, rated to pressurize to 7500 kPa, can consume 7.5 kw at max operational capacity.
Cryo Cell: Maybe not immediately concerning to your average pipe enthusiast, the cryo cell is nonetheless an atmospheric utility. It's connected to a pipe network that hopefully has chilled oxygen, which can be used to put a patient in stasis and heal some of their wounds. See the guide to medicine for more info.
Pressure Regulator: Effectively 1000L, 500L/s, no power usage
Manual Valve: no volume
Digital Valve: no volume, fucked up
Gas Pump: Effectively 400L, 200L/s, rated to pressurize to 7500 kPa, can consume 7.5 kw
High Power Pump: Effectively 400L, 200L/s, rated to pressurize to 15000 kPa, can consume 15 kw
T-Valve: no volume
Digital T-Valve: no volume, fucked up
(Omni) Gas Filter: 600-600L, 200L/s, rated to pressurize up to 7500 kPa, can consume up to 7.5 kw
(Omni) Gas Mixer: 600-800L, 200L/s, rated to pressurize up to 7500 kPa, can consume up to 7.5 kw
Portable Air Pump:
Portable Scrubber:
Hydroponics Tray:
