Gas Filter

The Gas Filter is a pipe building used to separate one chosen gas from a mixed gas stream. It has two outputs: the orange center output sends out the selected gas, while the green output sends everything else. This makes it useful anywhere mixed gases need to be split into dedicated lines, such as routing Hydrogen from an Electrolyzer to a separate pipe for use in a Hydrogen Generator.

A Gas Filter only consumes power while gas is actually flowing through it, so its cost depends on how often the line is active. Because of that, it is usually best to filter the most common gas first, then the next most common, and so on, rather than chaining filters in an arbitrary order. One practical way to estimate gas composition is to pump the surrounding gas into a Gas Reservoir until it fills, then inspect the contents.

• A filter line can be planned around the expected gas mix to reduce wasted power.
• In later stages, Gas Filters are often replaced by automation-based sorting setups built from refined metal and related research, since multiple active filters can become a noticeable power drain.
• Those cheaper alternatives use far less power, but they do not behave exactly like a Gas Filter: if power is lost, they can pass gas unfiltered, and they may misroute gas when the pipe is backed up.
• A more robust automated layout can be protected with a Smart Battery and logic to stop filtering when power is insufficient.
• Simpler bridge-and-shutoff gas sorting setups also exist; they are more bulky and usually need to be primed with an initial packet of the gas being filtered, but they never output the wrong gas under normal conditions.