Alas, the water drainage pipes in my home have developed a singing sound with a frequency of 400 Hz. This is slightly above a G note on the musical scale. The singing occurs when someone has finished taking a shower on the second floor.
Here is a sound recording: pipes_singing.mp3
We have a plumber coming to fix the problem tomorrow. He said that the pressure-reducing valve may need adjustment.
– Tom Irvine
Very interesting – your roof air vents may be a flute? That sounds like a resonant air column to me…beautiful
John Bretz
IADS Development & Support
(661)277-5410
(661)273-7003 x205
In my case it was the water supply, not the drain, causing the problem. I thought it might be a resonant cousin of waterhammer, but attempts to detune it with water-hammer suppressors had zero effect. The whole-house pressure regulator proved to be the source. I’m sure plumbing drain vents can work like a Incan pan flute, but I’d expect a deep bass note. The pressure regulator was making a fixed mid-tone pitch, in the middle C-ish range, though I didn’t measure it.