Review on 🐠 Pawfly 3-Way Aquarium Air Flow Control Lever Valve Distributor Splitter Pump Accessories with Check Valves & Suction Cups: A Comprehensive Set for Optimal Airflow by Ashley Rogers

I use it with the vacuum line in the bio lab. This is not ultra-high vacuum, but standard in-house piping that is weaker than the vacuum produced by a directly connected pump. I noticed a small flow of air through the closed valves. OK for my purpose, but I have yet to close the main valve on my lab bench. After a month of use, I noticed that the black plastic plug that seals the line behind the valves was becoming cracked and brittle. Everything is fine, but the valves should close normally! In particular, using these valves for vacuum is equivalent to reversing the airflow. Valves must be tight.