Fuel line and RCS

[nothingSpecial]

Hello.

I want to design a little asymmetrical multipurpose builder-tug for stations and interplanetary ships.

I know there are some mods for fuel and RCS balancing, but I want to keep their number as low as possible (even in my almost stock purist mood I have 15 of them in my Gamedata, mostly for bug fixes and information), and it also is more fun to make this with stock mechanics using only engineering skills.

So.

1. Is monoprop consumed equally from all the tanks (like if 1 unit spent from one tank, 1 unit spent from another even though they are different), or it is consumed proportionally (like 1 unit from 50 liter tank for each 2 units from 100 liter tank)?

2. Do fuel lines have any effect on monoprop? I know that both RCS thrusters and monoprop engines consume it from all the tanks of the craft, so this is a serious question.

3. If I loop two tanks with fuel lines, 1 --> 2 and 1 <-- 2, what will be the result in fuel consumption? This question consider both LFO and monoprop tanks.

The core of design is to make a tug with lateral docking port and with central and lateral (opposite to lateral docking port) tanks, with resource dumped from central to lateral tank to balance craft. The end question is, can this resource be a useful one (preferably monoprop) to save resulting weight, so I need to know fuel line behavior - and as a result, know how will it affect balancing of craft.

Edited August 29, 2015 by nothingSpecial

[Mastikator]

Monoprop is always consumed equally, fuel ducts don't work on them. But you can transfer manually.

[mhoram]

For Monoprop:

Fuel Lines have no effect on the consumption.

However staging has. The early stages are drained first.

Yes, Monoprop is drained equally and not procentually from all tanks.

For LF&Ox:

Don't make loops between tanks. This leads only to problems, because they will get drained asymmetrically.

Edit: Might be useful: http://forum.kerbalspaceprogram.com/threads/64362-Fuel-Flow-Rules-%280-23-5%29

Edited August 29, 2015 by mhoram

[nothingSpecial]

Thank you all! That was helpful.

So design won't be complicated, yet some micromanagement will be necessary.