Talk:Inlet Pump/@comment-12.204.184.82-20130515153515/@comment-27186955-20160131101952

It might just be that the pumps don't want cloggy obsidian.

If the pumps are in the same place for water and lava, then the game might try to prevent  the lava turning into obsidian on contact with the water, as that would cover the pump and cause it to pop out of place.