ceramic pipes with LOX breaking in vacuum?

[habuky]

 

I have liquid oxygen that is piped through isolated ceramic pipes to my rocket. While the rocket is in space, the oxygen stays in the pipes. Now the temperature of the LOX rises visibly until the pipes break. The pipes are in vacuum and should have nothing to exchange  heat with (except the pipe itself ?). To exclude the heat from the rockets exhaust, I spawned fresh pipes using the debug tool but this didn't changed anything. The smaller packet exploit would not work: as soon the tank is full, the LOX gets stuck in the pipes and accumulates to bigger packets.

I have two main questions:

1) Why ?  

2) What can I do against that? (Emptying the pipe every time after a rocket launch manually appears quite cumbersome and expensive to me.)

Save file attached if needed.

N20 280 pipes breaking.sav

[crypticorb]

Without loading up your save, is it because the pipes themselves are warming the LOX?

What you could do to fix your pipe problem is to only allow a specific amount of LOX through to the rocket. When you have the LOX tank filled, have a diverting loop from the rocket that loops back to a holding tank.

I'll be a while before I can take a close look.

[Neotuck]

9 minutes ago, habuky said:

1) Why ?

while temperature doesn't transfer to the vacuum the pipes themselves are warm and are heating up the LOX

only thing you can do is limit the packets of LOX under 1kg until the pipes become cold enough to handle the LOX

In this regard it's better to use radiant pipes instead of insulated ones to cool the pipes faster, you won't have to worry about the pipes heating up again in a vacuum

[crypticorb]

3 minutes ago, Neotuck said:

while temperature doesn't transfer to the vacuum the pipes themselves are warm and are heating up the LOX

only thing you can do is limit the packets of LOX under 1kg until the pipes become cold enough to handle the LOX

In this regard it's better to use radiant pipes instead of insulated ones to cool the pipes faster, you won't have to worry about the pipes heating up again in a vacuum

If vacuum is used, I'd use normal granite pipes, refined metal ain't cheap.

[Neotuck]

11 minutes ago, crypticorb said:

If vacuum is used, I'd use normal granite pipes, refined metal ain't cheap.

guess it depends on where you are with refined metal production

I usually have a good supply of iron long before I try building my first rocket

[habuky]

1 hour ago, Neotuck said:

only thing you can do is limit the packets of LOX under 1kg until the pipes become cold enough to handle the LOX

Thanks! I will try that. Iron or gold luckily isn't a problem.

But this means there is no "legal" way implemented yet?

[Fischer_L]

50 minutes ago, habuky said:

Thanks! I will try that. Iron or gold luckily isn't a problem.

But this means there is no "legal" way implemented yet?

What are you meaning by legal way? The pipes, even insulated one, must be cold enough to safely transfer LOX. It can be achieved in vacuum by looping something cold through them. It can be done with a "exploity" 1 kg packets, or full 10kg packets... but then you must watch out for temperature of you cold agent (LOX). Or you can just setup some overflow automation for emtying the pipes.

[tzionut]

The best solution is to cool LOX whit an aquatuner so when it arrive at the rocket tank it will be in liquid state so no pipe damage. 

[Gurgel]

I have loop that feeds the lox back into the lox-tank when the rocket is full. That way it stays cooled and when I switch off the pump, the pipes empty themselves. Solved this issue for me nicely. The loop is the lox-feeder:

 

[Saturnus]

4 hours ago, Neotuck said:

guess it depends on where you are with refined metal production

I usually have a good supply of iron long before I try building my first rocket

Well, yeah, it's literally raining down iron from space

[habuky]

6 hours ago, Gurgel said:

when I switch off the pump

Sweet solution! 

5 hours ago, Gurgel said:

I have loop that feeds the lox back into the lox-tank when the rocket is full.

If you place a liquid element detector + memory gate on the feedback loop behind the rocket the pump will be switched off automatically.

[Gurgel]

2 hours ago, habuky said:

Sweet solution! 

If you place a liquid element detector + memory gate on the feedback loop behind the rocket the pump will be switched off automatically.

Thanks! Yes, can be automated further. So far I was too lazy

 

[CherryHavoc]

I was doing some maths yesterday regarding the steam engine on my rocket and figured that if you know your pump is going to be pumping at full capacity you can get it to turn on for the perfect amount of seconds to pump the amount you need and no more.

That said, it hasn't really been a problem lately though it was at the beginning. Like the others have said, I think my pipes must have heated up so it doesn't change state.

[clickrush]

9 hours ago, Saturnus said:

Well, yeah, it's literally raining down iron from space

I'd still use gold for this though as will cool down almost 4x faster.

 

1 hour ago, CherryHavoc said:

I was doing some maths yesterday regarding the steam engine on my rocket and figured that if you know your pump is going to be pumping at full capacity you can get it to turn on for the perfect amount of seconds to pump the amount you need and no more.

That said, it hasn't really been a problem lately though it was at the beginning. Like the others have said, I think my pipes must have heated up so it doesn't change state.

Steam is usually far less of an issue because you can heat it up sufficiently so it wont condense in ceramic pipes until it reaches your rocket as long as you make sure it never stands still.

[Saturnus]

57 minutes ago, clickrush said:

I'd still use gold for this though as will cool down almost 4x faster.

True. Personally I prefer fail safe methods like this where you limit the flow to 1000g/s until the content of the pipe at the end of the pipe have reached a low enough temperature that it's safe to send full packets through thereby eliminating the need to manually oversee the process.

[clickrush]

17 minutes ago, Saturnus said:

True. Personally I prefer fail safe methods like this where you limit the flow to 1000g/s until the content of the pipe at the end of the pipe have reached a low enough temperature that it's safe to send full packets through thereby eliminating the need to manually oversee the process.

That's actually great advice. I almost never use provisional automation but that actually makes a lot of sense for long priming processes.

[Sundance]

Acutally since you're using pipes in vacuum, insulated ones are the absolute worst possible choice, you just gotta cool down your pipes before actually running the lox through there.. and using any highly reactive material to pre-cool those would be best and you'll loose even less cold when running the lox through there in the end.

That's just how i run the stuff from anywhere on the map to my rocket without losing even 0,1°, since.. vacuum and meh... it's the pipe doing the heating

[Cipupec2]

37 minutes ago, Saturnus said:

True. Personally I prefer fail safe methods like this where you limit the flow to 1000g/s until the content of the pipe at the end of the pipe have reached a low enough temperature that it's safe to send full packets through thereby eliminating the need to manually oversee the process.

What is the 1kg packet trick.you guys are talking about? The shutoff connects to the output side of the bridge, right? 

[Saturnus]

4 minutes ago, Cipupec2 said:

What is the 1kg packet trick.you guys are talking about? The shutoff connects to the output side of the bridge, right? 

The 1kg packet trick is that packets of 10% or less of the pipe maximum volume does not break pipes if the content would normally phase change in the pipe. The example above wasn't actually a working example of a limiting valve with a bypass shut off. I posted the wrong image This is a working example though.

[acolyteofrocket]

2 hours ago, Saturnus said:

The 1kg packet trick is that packets of 10% or less of the pipe maximum volume does not break pipes if the content would normally phase change in the pipe.

Do you know if this will be left in by the developers ? or do they consider it a problem ?

It seems to me that if they do not permit phase changes in a pipe then there is no way they can be cooled down from the inside - they might intentionally leave this in to allow this sort of thing to happen.

 

[Saturnus]

Just now, acolyteofrocket said:

Do you know if this will be left in by the developers ? or do they consider it a problem ?

It seems to me that if they do not permit phase changes in a pipe then there is no way they can be cooled down from the inside - they might intentionally leave this in to allow this sort of thing to happen.

I can't possibly say. It is something that has entered the game recently (as in the last 6-7 months) so it seems the devs put it in the game on purpose.