Filter (Water)

The water filter catches water. In the game data the filter type is Steam, i.e. Steam, water vapour – in the Filtration the slot logic value FilterType reports that type. The game code, however, lets every gas filter take the liquid form of its gas along: liquid water arriving with the gas is caught too. The reserve starts at 100.

Steam forms in several places:

• Hydrogen burns to steam: 2 mol of hydrogen and 1 mol of oxygen give 3 mol of steam.
• Alcohol burns to carbon dioxide and steam.
• Evaporation: water in an empty line partly evaporates until its vapour pressure is reached. At 100 kPa water only boils at about 384 K in the game.

At 72 J per mole and kelvin steam stores a lot of heat – more than three times as much as nitrogen. Cooled down, it turns liquid again, right up to 643.7 K once the pressure is high enough. That is exactly what makes it dangerous in a gas pipe: more than 2 % liquid damages a gas pipe. If you take the steam out with this filter before the gas cools, the line stays dry.

What to do with the filtered steam: let it condense and use it as water, for example with a Condensation Chamber. For liquid polluted water there is a separate filter (Polluted Water).

Lifetime: every 145 ticks in which it actually catches water cost 1 point of reserve; 100 points last a good two hours of continuous use. The medium version lasts about five times, the heavy one about twenty times as long, made in the Hydraulic Pipe Bender. The catalytic one (about eighty times) is only available from the trader Cosmic Curiosities. More in Evaporating, condensing, freezing: using phases on purpose and Filtration: separating gases, changing filters, getting rid of waste gases.