At work we use these
every day to evaporate small quantities of solvents from test tubes full of sample. The evaporators are in the hood; we pipe dry nitrogen to them from a regular lab-sized size T cylinder, chained right next to the hood. The problem is that no matter how I adjust the regulator on the gas cylinder, it emits a high-pitched whine that IMO is more than just annoying -- it may pose a hazard to anyone with chronic exposure to the sound.
The evaporator requires low-pressure gas (not to exceed 2 psi), and when it's operating the flowrate is probably liters per minute. (Unfortunately I don't have a flowmeter that goes that high.) I think the problem is that most laboratory regulators are not designed to supply such high flowrates. I've tried three regulators like this one
that I had lying around, all with different second-stage delivery pressures, but all of them make the same noise.
So, my questions: Is there something I can do to reduce the noise emitted by my current regulator? Or, if not, what are the magic words that I should look for in a replacement regulator?