Bug - Radially attached nose cones break fuel crossfeed

[GusTurbo]

Version: 1.0.2.842

Attaching boosters by their nose cones will break normal fuel flow rules. Fuel will flow outward through the decouplers. Originally posted about in this thread: http://forum.kerbalspaceprogram.com/threads/118597-Decouplers-nose-cones-now-do-crossfeed

See video below for a demonstration of this effect:

Re-creation steps:

Create a core stage and attach radial decouplers. Radially attach nose cones to the decouplers. Then, add fuel tanks and engines below the nose cones. The outer stages will draw fuel from the core, across the decouplers (which are not crossfeed compatible). If you attach the fuel tanks to the radial decouplers, fuel will not flow across them (the correct behavior).

[LABHOUSE]

That is leftover from back when there were no fuel lines, decouplers provided fuel flow.

[GusTurbo]

How does that explain the interaction with the nose cones? Did you watch the video?

[LABHOUSE]

I do not know why it is only with the nosecones that it sneaks back in, and yes I watched it.

[Claw]

Hey Gus,

This is actually a strange reaction to anchored decouplers. You'll note that there's not a "No Fuel Crossfeed" note in the info window. Anchored decouplers have a bit of an odd fuel flow rule (non standard) in that they will crossfeed except when the part mounted to them is a fuel tank. So normal fuel operations that we are used to won't cause a problem. But if you connect any other fuel crossfeed capable part to the decoupler (like a nose cone), fuel will flow.

This is something I will be including in my next Stock Bug Fix release.

Cheers,

~Claw

[GusTurbo]

By "anchored," do you mean the high clearance decouplers that I used in this craft?

[Supernovy]

Anchored decouplers is any radial decoupler that leaves behind a small greeble on the craft when decoupled. In stock this is every radial decoupler except the structural pylon.

In the case Claw is talking about, attaching a fuel tank directly to a fuel tank will not crossfeed, but attaching a radially attachable crossfeed capable part, then stack attaching a tank to that part will crossfeed. The same works across radial decouplers if they have no crossfeed, which is what's happening here.

If you config edit the decouplers to not be crossfeed capable, this will stop.

[Claw]

Yeah, what Novy said. Sorry if I threw in some confusion there. Anchored Decoupler is what the code is called that the radial decouplers use.