Many Unit Operations experiments involve have a supply of Nitrogen from a Nitrogen cylinder. For example, part of the Mass Transfer in Agitated Vessel experiment requires a stream of Nitrogen being send at a pressure of 40 psi. However, when we arrived and check the apparatus, it seemed like the Nitrogen tank was nearly empty. We opened both the cylinder valve and regulator valve all the way, and the pressure is still below the desired pressure. We consulted with the professor and the TA about it and a fresh tank arrived soon.
After strapping the tank to the wall and taking all other safety precautions, we hooked up the nitrogen line with the process line. The line was connected and tightened with a wrench to the best of muscle strength. However, in order to check to make sure there’s no leaking at the joint, my lab partner Tom came up with a custom way to test it. Basically, he made some soapy water solution, and made a few drops on the joint. If there’s a gas leak, soap bubbles will appear. Tom placed a few drops, and no bubbles!
Applying knowledge beyond school is always inspiring to me. We were able to use something that wasn’t written in the lab manual to promote lab safety. The lab turned out to be the way we wanted, thanks to a few drops of soapy water!