Try to use the "Place Lava" mode of an Infernal Chalice when the contents of the chalice are less than or equal to the space of the destination. It will place the lava, but not set the chalice contents to zero! This is powerful in a modded environment that has larger tanks for destinations, but is NOT a result of mod interaction. This bug was reproduced in Minecraft 1.10.2 with Forge 1.10.2-12.18.3.2254 using Reliquary 1.10.2-1.3.3.639 as the only mod loaded.

To reproduce:

1. Craft an Infernal Chalice
2. Sneak + Use Chalice to switch mode to "Drain"
3. Use Chalice to drain one lava source block
4. Sneak + Use Chalice to switch mode to "Place"
5. Use Chalice to place infinite lava

This is a dupe bug and should be addressed immediately.
I would have contacted @P3pp3rF1y in private about this, but he does not have any contact information available on his GitHub profile, so... here's a report on your public issue tracker.

Hooray, it's fixed! Once this update gets published on Curse and my server owner updates the damned modpack, I can properly empty out some chalices and disassemble a very cheaty infinite RF source I was able to quickly put together that exploited this

This is now fixed in the latest version available on CF.