Factorio Forums

So this one has been driving me insane for weeks now, every so often this one pipe which is supposed to only contain heavy oil would seemingly randomly be filled with light oil.
At first it filled the entire pipe network before I added pumps to narrow it down where it was coming from since I thought I was going mad and had mixed the pipes somewhere. There is definitely no mixing or contamination and the pump is filtered for heavy oil only.
The only pattern I have been able to deduce is it happens after loading the save in an updated version. I thought that might be the case after it happening when loading in 2.0.15. Sure enough the light oil was back after updating to 2.0.16 and its now 3 in a row in 2.0.17.
Save File: https://drive.google.com/file/d/15Ks0Vv ... sp=sharing

This is most likely a duplicate of 119600 which was fixed for 2.0.18 and is pending a release. Basically a consequence of fluid segments merging fluids and pipe-to-grounds connecting in a weird order, sometimes ignoring pipe-to-grounds in between that were not yet setup during load.