[0.18.21] Fluids at different temperatures not equalizing, preventing train wagons from filling

[brysamo]

To start with I'll point out that this is an issue I'm having with a moded game The mod in particular that seems to be causing this is Angel's Smelting.

The issue is that I have a train with fluid wagons that is unable to fill more than 400 units per car on any auto setting. If I switch the train to manual it will fill, but each car will be shown as having a different fluid, as they are at different temperatures. this starting occurring when the mod was update to have realistic molten metal temperatures.
This only affects fluid train wagons. All pipes, machines, and tanks regardless of size are unaffected by this.

I brought it up on the mod forum but the current curator of the mod believes this is an issue with the game so I'm also reporting it here in case it is.

Here's the conversation from that post:

So I'm experiencing a weird issue with transporting molten glass by train (and honestly I'm not sure if the issue lies within Angel's or Bob's).

1 - Only molten fluids are affected
I thought this was just an issue with molten glass but it was the only molten fluid I was transporting. tried it with a few others and same deal.
2 - My train only fills if I put it to manual. I've tried every auto condition, only manual makes it actually fill. When on auto, it will fill with 400 units, and then stop
3 - The first time I did this it just showed the train as 1 single tank (ie, displayed 400k units when full). Now it shows each wagon separately
https://i.imgur.com/Suf17WT.jpg
4 - Destroying the train and rebuilding it didn't work
5 - Making a brand new train didn't work
6 - Destroying the whole station and all fluid didn't work
7 - The casters on the bottom making glass panes work fine
8 - Getting rid of the petrochem mod didn't work (but before i did that I tried the petrochem wagon, didn't work)

I should also add I'm not running the latest update of Angel's or Bob's because I don't want to reconfigure my factory to deal with RTGs that Bob's added for satellites this late in the game, but to troubleshoot I did update and the issue remained.
This was working perfectly fine when I first built it. I transported millions of units with no issues (there have been a bunch of updates to both Angel's and Bob's since then).

My best bet, with keeping the past updates in mind... Are the different fluids in the tanks for example, are they the same temperature? My guess would be they are a bit too cold, and when the train starts filling up, the tank is draining, so new hot fluid enters and the temperature can rise, when it bumps the temperature, the train stops filling? If this is the case, you should report this to the base game, as it is meant to equalize the temperature, so the fluid in the fluid wagon should rise as well, instead of stop filling. I did change the temperature on the smelting fluids to represent real life melting points, as requested on /r/factorio a while back.

[Honktown]

Do you have a save you can share? I'm trying to reproduce this with steam (vanilla has 165C and 500C steam), but am unable to.

Coincidence or related: A pump has a buffer of exactly 400 units, shown in the right side details when the pipe network has a fluid lock. If you have a circuit condition on your pumps, the circuit condition may be wrong: While the circuit condition enables the pump, it fills to 400, but when the train stops and you thought you had your circuit condition right, the pump is still "disabled", but sends the 400 units it had in buffer into the fluid wagon.

[brysamo]

https://mega.nz/file/wId1ya5Q#zrSLLVjoe ... 9HmpcoJwYY
There's no circuity involved here. This did not start happening until Angel's was updated to have realistic temperatures for molten recipes.
I just tried it with 765°C steam from one of my power plants and it did not experience this issue.

[Honktown]

From what it looks like, is when the train is stopped (automatic, when stop is capable of reading signals) an alternate fill logic or fluidbox is used by the pump.

The 400 units is coming from the buffer. This can be seen by picking up and putting down the pump (even the tier-1 in your game). The buffer fills instantly (24,000 units/sec if we're filling the buffer in 1 tick), but then it appears the pump is "replaced" by alternate fluidbox/stop logic that maxes out at the default temperature of 1000C.

I can confirm this is the result of no mod interactions. I have a cheat-y nuclear mod that can output steam over 1000C. With only that mod enabled I can make a minimal save: boiler steam + high-temp nuclear mixing into a storage tank, adjusting proportions manually and checking the pipes to see what temperature the pump is seeing. As soon as it sees under 1000C at the input it works fine, despite the pump fluidbox being set to work with >1000C and working with that while the train is not "stopped" at the station.

Edit: a slight correction is in order. The pump has to "disengage" from the wagon, no stop is required. When it's disengaged/retracted it can fill, but if you wiggle the train back and forth, when it engages it will dump 400 units and refuse to fill. Wiggle again, it can fill, wiggle again, it can empty...

Edit edit: This has an interesting consequence... I had a pump filling and a pump emptying with >1000C steam. If the timing is right you can actually get fluid trapped in the pump. Right before engaging it takes fluid, but then it engages before it has time to empty.

bug.jpg (176.94 KiB) Viewed 4245 times

[brysamo]

So then my options are to have the mod not use fluid over 1000°C or wait for whatever is causing this in the base game to be patched, correct?

[Honktown]

So then my options are to have the mod not use fluid over 1000°C or wait for whatever is causing this in the base game to be patched, correct?

The Factorio dev's can be quick to patch, but sometimes you have to wait for the next experimental.

One issue is even if the mod dev changes the temperature of the fluids, they are already in the pipes. The pipes need to be emptied/mixed or picked up so they can reach under 1000 C. A brutal way to handle it would be to change the recipes, and run a migration that checks *everything* that can hold fluid, and change the temperature 999 (for safety) or 1000 C. Might not take that long, but the code would need to check every entity on the surface without exploding ram.

If you wouldn't mind linking the mod dev, he can take some steps:
1) change recipes for now
2) in a migration, use a chunk iterator, and search for entities by chunk. This way at most you're only dealing with one chunk worth of entities at a time.

There'd be some ways to speed it up, but if I guessed I would miss *something*. The obvious things are assemblers, chemical plants, pipes, storage tanks, pumps, and fluid wagons. Anything that can handle the fluid needs the fluidbox checked, changed if needed, and re-written. Pretty straight-forward.

This should solve the issue. No promises.

[masterzh]

I came across this issue too. 0.18.22 here. So far only issue is steam. Seems that ramdomly it start dropping temperature or not accepting even proper "165 degree". if there is more then 1-2 pipes between factory and source of steam it will not accept it or "yes / no" randomly. As i am running a lot of mods i am clueless who caused this.

[Honktown]

I came across this issue too. 0.18.22 here. So far only issue is steam. Seems that ramdomly it start dropping temperature or not accepting even proper "165 degree". if there is more then 1-2 pipes between factory and source of steam it will not accept it or "yes / no" randomly. As i am running a lot of mods i am clueless who caused this.

Mind uploading save somewhere?

[masterzh]

Actually i solve it with global "pipe fluids" reset command on whole map. I think (just my guess as its 280h base) it was one of PY mod compressors. Output product was "steam" without any temperature so i assumed its "default" 165 degrees and it was connected to rest of base. Seems that after some 10-15 ingame hours it pushed its steam through and mixed with proper steam. I was troubleshooting by directly placing some steam hungry machine on output of various buildings producing it. (either that or some patch in-between but it could have been there doing bad bad stuff for long time as i have up to 300 buildings producing steam. 1 wrong one took very long time to push it along. Weirdly when it was mixed it showed 165 degrees steam in pipe but no building was able to accept it. Its all good now after mentioned reset and compressor disconnected.

[boskid]

Is this still happening in 0.18.35? I am trying to load that save file but 4 mods are not released and loading save fails seems to take forever when applying migrations for "angelsindustries". When i load this save file without angelsindustries there are no trains near me.

[brysamo]

Somewhere between 0.18.21 and 1.0 this appears to be fixed.