DescentBB

Spidey wrote:
http://nobackflow.com/toilet.htm

"no connection whatsoever"

wow. that site has a terrible understanding of how a toilet works.

the airgap is supposed to be behind the bowl, not the tank.

For such a situation to occur, you would have to have a burst pipe near where the municipal system ties into your home. Moreover, if there would be a backflow situation, it would be caused by a bad seal and the water would be pulled down to the lowest point in the house. This page is also assuming that sewer water would be pulled up from the bowl into the tank, which is physically impossible. Also, toilets are designed to contain any sewer gas in the airtrap near the back of the toilet bowl, not the tank. So any blue that you would see, is caused by copper corrosion.

No. Connection. What. So. Ever.

Site never says a word about water getting from the bowl to the tank, it refers to gasses, and the air gap they refer to is the very same one Krom mentioned in his post, not the trap behind the bowl, the gap the site mentions prevents tank water from getting into the valve.

It doesn’t matter anyway, the post you referred to was talking about tank water getting into the system, not a connection between the sewer lines and the supply lines.

amazing, simply amazing! We start with lead poisoning of the population and end up with valuable information on toilet/sewer connections.

Welcome to real life.

Spidey wrote:Site never says a word about water getting from the bowl to the tank

Uh yeah it does, right here.

between your drinking water and the contaminated water in your toilet tank

it refers to gasses, and the air gap they refer to is the very same one Krom mentioned in his post, not the trap behind the bowl, the gap the site mentions prevents tank water from getting into the valve.

It doesn’t matter anyway, the post you referred to was talking about tank water getting into the system, not a connection between the sewer lines and the supply lines.

and I refuted it directly (seriously, who writes this crap these days?). If you had read what I wrote, you'd see I was reinforcing Krom's position. But thanks for demonstrating selective reading, mister comprehension.


As for the lead pipe debacle in Flint, you wouldn't see that here in Canada. Our "evil libtards" keep that stuff in check.

Talk about comprehension…anybody else see the problem with the first two quotes in the above post?

Only you do.

i don't care if you called me a dumbass. not a big deal; we're both adults, and we can take a little insult or two without going 'wah someone called me a name on the internet boohoohoo'. No, what got me going was that showed me a site that was factually wrong and that you tried to use it as backup. Now, you try and cover yourself by pulling reading comprehension? That just weak and insulting.

Well, the site is not factually wrong it’s actually spot on.

The problem with those two quotes is simple…

The top one says “tank” and “bowl”
The second one says “tank” and “supply”

Two different things.

And yes…there is no way water can get from the bowl to the tank, the site never claims that, the side claims that “gasses” can get from the sewer to the tank.

Anybody that understands fluid dynamics can understand how gasses can flow “up” a downstream water flow induced by gravity. You can easily demonstrate this with a strobe light directed at an open faucet…notice that water doesn’t flow as a contiguous stream, it’s broken into droplets, and there are gaps between those droplets, those gaps can allow gas to travel against the stream. You also must understand that a gas trap is only fully effective when the water is standing still, very hard to calculate the effect when there is as much turbulence as there is in a toilet flush.

As far as how much sewer gas can get into the tank and under what circumstances…well that can be debated.

So I’m done now, you can have the last word, if you feel the need, and yea “dumbass” was only adult banter…nothing really meant by it.

Spidey wrote:Anybody that understands fluid dynamics can understand how gasses can flow “up” a downstream water flow induced by gravity. You can easily demonstrate this with a strobe light directed at an open faucet…notice that water doesn’t flow as a contiguous stream, it’s broken into droplets, and there are gaps between those droplets, those gaps can allow gas to travel against the stream. You also must understand that a gas trap is only fully effective when the water is standing still, very hard to calculate the effect when there is as much turbulence as there is in a toilet flush.

Like you said, anyone with an understanding of fluid dynamics would know that if any fluid is going one way, especially if fed via pump or gravity, would know that gasses would not flow up the pipe. It's physically impossible. What happens is the ambient gasses (the air you breathe) gets sucked in through the bowl due to the fact the water level drops pretty fast. But what you say about the gas trap only being effective when the water is still (providing a positive seal) is absolutely true.

If gas were to go up the stream, that means the other end is capped.

As for the water breaking up into droplets, that's our friend surface tension at work.

Here's a (rather extreme) example: A hydroelectric dam. When they let the water through, either to generate electricity or to drop the level in the reservoir, do you see any bubbles on the inlet side? Nope. That's because gas, being lighter than liquid, is forced out from the outflow. Try it sometime. All you need is a syringe, and a tube. It doesn't even need the plunger.

Physics is fun, and there really is a fair bit of science behind the lowly loo.