On Feb 4, 4:58*am, Jeff Thies wrote:
On 2/4/2011 7:28 AM, Bob Villa wrote:





On Feb 3, 7:47 pm, Jeff *wrote:
On 2/3/2011 12:59 PM, Bob Villa wrote:

On Feb 3, 10:22 am, * *wrote:
Bob Villa wrote:
On Feb 3, 8:55 am, "Robert * *wrote:
* *wrote in message

...

....comes from the water stored in the tank, vs the incoming water
pressure? I'm referring to an old style toilet, not some dubious
low flush annoy-o-lator.

Anything with a tank is gravity powered. Incoming water, AFAIK, has
nothing to do with flushing, just refilling the tank. I'll bet those
old "Godfather I" type toilets with the ceiling-high tank could
flush a bag of golf balls. Some tankless toilets run off water
pressure, but I've not seen them (here comes the flood of those that
have!) in anything but commercial structures.

--
Bobby G.

I doubt the height added pressure...it's not like it was the depth of
the water, it was just falling farther.

height does add pressure. there's that gravity thing increasing the speed of
the falling water.

The water can only fall at a certain speed though a given
diameter...no matter what height.

Actually, the calculations are widely available as they are used in
irrigation, amongst other applications. *There is not a lot of head loss
for that large a pipe. Velocity being a factor of pressure, area and
resistance. The restrictions largely seem to be in the toilet itself,
not the water column.

* *I think the key is a direct path to flush the effluent rather filling
up the bowl. In a poorly designed toilet the bowl will fill and that
height of water in the bowl will push out the waste. Sort of like tuning
exhaust lines in a car.

* * Jeff

At least, that's how I see it. If there was a column of water and it
was release at the bottom...then you would see some pressure.

So...are you saying the height makes a difference in pressure or
not...I not quite sure??? Sounds like if you design it right it
doesn't make a difference!

* *The height absolutely makes a difference in pressure. In my "super
flusher", the tank fills all the way up, but it does not drain all the
way down (unless you hold down the handle). The minimum column height is
greater.

* *What I think is more important is how it drains. If it doesn't drain
well the bowl simply fills instead of flushing away. The weakest link is
in the draining, not the filling, although both need attention.

* Ive noticed that nothing sticks to my toilet bowl, so resistance is
less there also. You are trying to flush solids not water. The water
path in my "super flusher" is directly in line with the waste. That is a
direct flow, with the waste in the middle.

* *So, what I am saying is that while more pressure is good, it is not
the answer. Good design is.

* *Jeff- Hide quoted text -

- Show quoted text -

But really, when the flush valve opens, the pressure is not what
operates, it is the velocity of the water. The pressure is what gets
you the velocity. Thus it doesn't matter what the pressure in the
mains is, your tank height is all that counts. Even the "pressure
assists" operate the same way.

You don't have "pressure" unless the water is confined in something.

Harry K