Calling all plumbers in here to try and help me pinpoint an issue in my condo.
I have an annoying high pitched noise (about 300-500hz) when people in my building run water.
Here's a link to the audio file (enhanced by me):
I finally got access to the valve room for the building and here's what I found. What could be causing such a noise? I can't tell management 'replace everything'
If you think the source of the noise is in that room, I would get a plumber involved. The black piping on the right is the fire protection (sprinkler) system. The contraption in the copper piping you highlighted in your pictures looks like a Watts 007 double check valve. You don’t want to tinker with any of that.
I am getting a plumber involved, but since the noise is intermittent, there's no guarantee they will be able to hear it while here. So I need to tell them what to look at.
Though, it appears the noise is coming from the double check valve (rpz backflow)
From what I can hear, this just aliens trying to make contact, no big deal.