Minecraft Version 1.12.2

Forge Version 2707

Mod Version 1.12.2-0.7.3-239

Describe your problem, including steps to reproduce it

Build a pressure chamber
Place a vacuum pump next to the pressure chamber valve with the negative side pointing to it
Place a creative compressor and set its pressure to 5 bar
Put 10 speed upgrades in the vacuum pump and wait for a few seconds
Not only the pressure chamber have negative air volume

but also the vacuum pump

Any other comments?

Yeah looks a bit derpy but it shouldn't be anything more than a cosmetic problem. Will get it sorted for the next release though.

Fixed in 0.7.6 release