Liquid reservoir

[DAN-di-WARhol]

What's the point of a liquid reservoir if it needs an output to operate? I thought the point of it was to STORE liquid... (?) I may as well pump it into a hole.

[Bokonon]

If you pump it into a hole you need another pump to do something with it from there. A reservoir has output so you don't need another pump. Add a shutoff after the output and you can fill the reservoir without immediately using the contents.

They're also useful for buffer/overflow purposes. An example (same works for gas reservoirs and it's the same principle) would be natural gas. You want to pump it out before the vent overpressures but you don't need it all at once. Pump it into a series of reservoirs on the way to natural gas generators, you'll only use what you need, you'll maximize the vent by not overpressuring and the stored gas will help get through dormant periods.

Edit: That said, it's always situational, sometimes dumping it into a pit (or a sealed room in the case of gas) is the better choice.

Edit 2: Another very common use: liquid reservoirs (with automation) in a sealed room filled with chlorine gas are the best way to remove germs from water.

[DAN-di-WARhol]

Hmmm. Okay. But how (why?) does the output work? Surely if it goes in at the top and out at the bottom then it isn't storing anything?

[MoKuS]

A hole is better since it takes more liquid inside. You need ore to make a reservoir which is another minus. You however don't need a pump and electricity for the reservoir.

[gimmethegepgun]

The output won't output anything if the output pipe is backed up. If it leads into a generator or some other thing that needs the output, or you use a valve to block it, then it will store whatever comes in until it's able to leave.

[Hedning]

One thing I always used the reservoirs for is for my oil refinery. Let the oil refinery work until its full, then shut it off until it's empty. If you do not control the refinery this way your dupe will run down as soon as 1 pipe tile of petroleum has been used and he will turn the wheel once producing 10kg of petroleum, then the pipe will be full again and cancel further production, and repeat. This wastes a lot of time for the dupe travelling back and forth.

As others have said the point of the reservoir is the free pump in its output. You are essentially storing the liquid in the pipe system so that you won't have to pay 240W to pump it back in again.

[Angpaur]

There is an easy trick to stop the reservoir from outputting - you build it on mechanized airlock and open it via automation when you don't want the reservoir to output anything. This can be hooked up to reservoir port and you make it close the door when reservoir is full and it will then start outputting.

Also reservoirs need only input pipe to be connected to be able to store. If you don't want anything to be output then don't connect pipe to output port.

[Bokonon]

Originally posted by DAN-di-WARhol:

Hmmm. Okay. But how (why?) does the output work? Surely if it goes in at the top and out at the bottom then it isn't storing anything?

Because unlike real life, gravity has no effect on plumbing. The liquid really doesn't go "in at the top and out at the bottom" like you seem to think it does. Yeah, technically the input is higher than the output but this has nothing to do with how it functions, it's just graphical. A mod could flip it so the input is lower than the output and the reservoir would function exactly the same otherwise. It's like Hedning said, once it's pumped into pipes it will flow, storing it in a reservoir maintains this "in the pipes" state eliminating the need to pump it again (which as said costs power).

Edit: And as has already been said, you do not need to let the liquid immediately exit the tank, you have multiple ways of accomplishing this.

[Druckform | INSOMNIAC 3D]

just have a pipe coming 1 block out of the output, then it will let you fill it up, same goes if you dont have an input and want to extract the liquid, just put a pipe 1 block across the input.

[gimmethegepgun]

Originally posted by Piggy:

just have a pipe coming 1 block out of the output, then it will let you fill it up, same goes if you dont have an input and want to extract the liquid, just put a pipe 1 block across the input.

You don't need a pipe on both sides for it to function, just a pipe on the side you want to use.

[Angpaur]

You need to have both pipes if you want the reservoir to output liquids.

[SkyKaptn]

Another benefit of the reservoir is to equalize multiple water temperatures from different pipes. This is very useful to have in front of an aquatuner if it depends on a temperature sensor/shutoff

[Hedning]

If you have different pipes shouldn't you have different aquatuners? Otherwise you'll have a bottleneck.

[SkyKaptn]

Originally posted by Hedning:

If you have different pipes shouldn't you have different aquatuners? Otherwise you'll have a bottleneck.

Besides the point. The fact that the reservoir works as a "blender" of different temperatures is my point here. Use that function as you please in your setup.

Edit: Another very good (crucial) use for a reservoir as a "blender" is in a oil cooled metal refinery coupled with the steam turbine:
-Using shutoffs the hot oil from the metal refinery has priority to avoid clogging and goes straight to a reservoir. Here it will blend with the cooled oil from the steam turbine, ready to be used as coolant again. (800 liters + minimum 400 liters for continuous operation)

Edit II:
Use the blender for 0 extra power cost for safe plant watering if you have both ice cold and hot water.

[Aranador]

this 'blending' or homogenising idea is critical when needing to hit a very precise temperature target, such as when creating liquid hydrogen. With an aquatuner dropping a liquit temperature by 14 degrees, dropping the packets into a sufficiently full reservoir allows you to change the average temperature by a much smaller amount before it flows around your cooling loop.

Tanks are capable of storing excess to account for uneven supply, but they also have a lot of other applications, Working those out is part of progressing from a new player to an experienced player - good luck on your journey.

[Hedning]

Originally posted by SkyKaptn:

Edit: Another very good (crucial) use for a reservoir as a "blender" is in a oil cooled metal refinery coupled with the steam turbine:
-Using shutoffs the hot oil from the metal refinery has priority to avoid clogging and goes straight to a reservoir. Here it will blend with the cooled oil from the steam turbine, ready to be used as coolant again. (800 liters + minimum 400 liters for continuous operation)

That's very interesting, because my liquid reservoirs seem to be insulating the contents, so for the metal refinery I instead use radiant pipes to exchange heat with the coolant and the steam.