You are right that the water above your work site is draining slowly. A simple solution to that is to open the faucets at the top of the pipe stack feeding the place you are at. Since you normally don't know how the pipes are run, just open up all the faucets in the house, after of course closing the main feed.
To say nothing of the mechanical/plumbing equivalent of an inductor, the mass of the water in the pipe. I used to run into that when turning off my lawn sprinklers; the sudden drop in current (water flow) in the pipes caused a thunk analogous to ringing in an inductor when a switch is opened. Since having put in automatic valves I don't pay much attention to how much of a thunk happens anymore.
A few years ago we started getting pinhole leaks more and more often at our house, so we had the guys come in and replace the old copper pipes with PEX, crosslinked polyethylene. It was supposed to be quieter than copper but was anything but. The plumbers installed a ~1 gallon tank by the water heater, and I assume it is supposed to act like a capacitor to resonate out the inductance (mass) of the water in the pipes.
Well, it didn't help, and after several weeks of back and forth, the manufacturer of the shower valves, Moen, replaced them and the noise went away. Moen claimed that the installation of the valves was faulty. We never did find out what caused all the noise, but it's gone, and that was the main outcome we were looking for.
Glen, I've passed the link to your story on to one of the techs here. Hopefully he can learn some good electronics from it. Thanks!
@David or the thyristor is triggered (ie the syphon is primed) ??
Good analogy, and if you include a resistor and discharged capacitor as the thyristor load, the charged capacitor will discharge into the other capacitor. When the levels (voltage) equalizes the current will stop flowing, just like a real syphon.
Sure hate to tell you this but that pin hole may be due to acidic water. You might get it tested to see if the pH is below 7.2 or so. The acid etches away the inside of copper pipe. If that is so, I would expect you will have more leaks in the future.
Hi Crusty..... "I do not sure there is the equivalent of a syphon, in an electronic circuit? I am sure there is someone out there that can say there is."
Nice challenge!! How about a diac or a thyristor in a Capacitor-Discharge Ignirion or photoflash circuit? The cap represents the bucket of water, which will not be drained unitl the diac reaches its breakdown voltage (ie the level of the water is high enough, like an automatic toilet flush) or the thyristor is triggered (ie the syphon is primed) ??
It's an interesting problem especially if the upstream and down stream bowls do not cause the problem bowl to suck or rise and fall.
I do not sure there is the equivalent of a syphon, in an electronic circuit? I am sure there is someone out there that can say there is.
I had this problem once on a house I refurbished, turned out that the bowl was the problem the geometry of the the P or S outflow from the bowl was that the outfall side was slightly lower than the standing water height in the bowl should be, and thus it sucked.
If you have a cheap e-bay USB waterproof camera "enderscope" you might be able to see what the inside of the pipe is like on the affected bowl and outflow.
Maybe there should be a third vent that never got installed. Or maybe one is clogged by a bird nest or dead squirrel.
Still remember seeing a schematic for a (Tek?) scope that showed a little cartoon image in the margin beside a BNC connector. The image was a wash basin on the outside of a small shack. The draftsperson had a sense of humour, the connector was labelled "external sync".
I've thought it might be related to venting, but could never figure out exactly what the problem was (or as Glen might say, the equivalent circuit). There are two vents on the roof...
Can you explain exactly where the breather needs to be, and what is causing the suction?
This toilet is on the main floor – there's one above and one below, which don't have this problem. Also, nothing affects the slow, steady suckout of the afflicted bowl (takes a couple minutes). I can flush other toilets and run other water – no impact on the current sink..., uh, current bowl.