it should still be in there.
Top of the technology-updates.lua file:
bobmods.lib.tech.add_recipe_unlock("fluid-handling", "bob-overflow-valve")
bobmods.lib.tech.add_recipe_unlock("fluid-handling", "bob-topup-valve")
bobmods.lib.tech.add_recipe_unlock("fluid-handling", "bob-storage-tank-all-corners")