How do aircraft carriers procure fresh water?

The engine doesn't take in anything for the boilers or for a reactor. The reactor has a sealed, distilled water source for cooling. It is in no way in connection with the potable water system for the simple fact of safety. What if there were a leak in the system? Radioactive waste would get into the potable water system. That's not good and a really stupid answer.

This is how you make fresh water from sea water...you distill it. You bring in sea water (by pump) into a big kettle looking thing. You put fire (heat) to it and bring to a boil and the steam that rises from it is condensed and stored in potable water tanks that is then treated with chlorine and fluoride (just like your tap water at home). From there it is piped all over the ship or submarine to various places like the kitchen, laundry (no, sea water is not used for washing clothes), the head (bathroom) and scuttlebutt's (water fountains). The heat source can come from different places. On nuclear powered vessels, super-heated compressed steam can be used as a heat source and they usually have several electric systems that can be used for axillary purposes like if there were a fire to be put out (yes, they use fresh water for fire fighting because of the corrosives of sea water). On non-nuclear powered vessels, they use the heat produced by the boiler-type steam plant that also provides the steam for the GT's (gas turbines).

It's all actually a very simple process. Heat the sea water, condense the steam and you have fresh water. The brine that is left (salt, sand and other minerals) is then flushed back out to sea. Ocean liners use the same process.

Fresh water is distilled from salt water and then stored in pot water tanks. It is then treated and pumed to the pot water system for people.to consume. It is NOT USED for flushing toilets and urinals. And on a aircraft carrier fire fighting is salt water. The water consumption per person per day is watched closely and not allowed to go above 25 gallons per person per day. This includes all uses of fresh water for laundry, cooking, and washing the planes. The ship also uses the distillers for feed water to make steam from the reactor. Where do you think the steam comes from for the engines ? Ask a boiler operator where the water comes from to make steam.

The engines take in sea water boil it and the steam condenses in the condenser unit which is a big refrigerator the water is now free of salt. The new fresh water is then used to run the boilers or reactors and is also used to give fresh water for the crew. Note;boilers and reactors usually have their own water supply and condensers to turn the used steam back into water to be used in the boilers or reactors again. I don't know the size of the water tanks. However the tanks are refilled by the ships desalination plant.

On a ship that carries that many people, will have to come up with a better system than water tanks. I am sure the U.S. Government has water recycling systems (regenerating systems) on their aircraft carriers that procure as you say fresh water.

Now when it comes to food, they stock up enough to feed their men till they reach the next port. To be sure each person gets enough to eat they work on portions this saves space and weight.

Laundry well they would have facilities large enough to cater for 5000 men.

Remember you are dealing with a vessel the size of two football fields. They cater for all your needs.

There is a fresh water processing plant on the carriers. Converting Salt Water to Fresh Water.

They have a desalination machine. They use salt water for washing clothes. They make their own fresh water from the salt.by distillation. There have been times when fuel was pumped overboard and then went in through the desalinators and made the drinking and cooking water taste of JP5. It also gave the runs to the crew. (Viet Nam era)

i dont exactly know how big their fresh water reservoir is but i know for a fact that they have a huge desalination plant in the ship which makes around half a million gallons of fresh water a day.

the same way submarines & all USN vessels do. "flash evaporators". it works like a whiskey still only it uses steam for the heat instead of fire. very interesting piece of machinery and requires very regular maintenance. a carrier has many of these and some can put out over 10K gallons a day. does that help?