How much of a toilet's power....

....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.

Reply to
JoeSpareBedroom
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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.

Reply to
Robert Green

I'll bet.

When I bought my toilet the sales girl referred to it as the "super flusher". Recently, I heard the rest of the story. The boys with bling had been coming in and asking for it that way. Word is the cops hate it!

Jeff

Reply to
Jeff Thies

Not quite. Some toilets and urinals have flushometers, that use water pressure, common in nyc apartments, and maybe there are other arrangements, but some other tank toilets are playing tricks on the eye**.

**Yes, I had a particularly loud toilet in a motel, so I took the lid off and there was some metal chamber with a distorted dome top filling the space. I guess it filled up the bladder with water pressure, compressing some air inside, and used that to flush. It's a good thing I was alone or it would have woken me every time it was used.
Reply to
mm

All of it.

Reply to
Tony Miklos

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

Reply to
Bob Villa

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

Reply to
chaniarts

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

Reply to
Bob Villa

Yes, but is the maximum speed reached when the bottom of the tank is an inch above the toilet, and the top of the water in the tank is about 12 inches higher than that? If not, wouldn't having a higher tank mean a speed closer to the maximum? Since the height of the water averages about 7 or 10 times as much with the tank right on th toilet.

I"ve used those toilets of course, but not since I started paying attention to this sort of thing.

Reply to
mm

"Bob F" wrote in message news:iif836$g1c$ snipped-for-privacy@news.eternal-september.org...

I'm with you because when I test flush my toilet, higher is better in terms of getting it to flush with a minimum amount of water in the bucket. I suspect that as toilet design improved, they found the ceiling high tank didn't need to be quite so high to do the deed. In looking up the history of toilets, there are tank type units that DO use pressure to flush:

Tank style with high-pressure or pressure-assist valve This system utilizes mains water pressure to pre-pressurize a plastic tank located inside of what otherwise appears to be the more typical ceramic flush tank. A flush cycle begins each time a user flushes the bowl. After a user flushes and the water in the pre-pressurized tank has finished emptying into the bowl, the outlet valve in the plastic tank shuts. Then the high pressure water from the city main refills the plastic tank. Inside the tank is an air-filled balloon-like rubber diaphragm. As the higher-pressure mains water enters the tank, the rubber diaphragm is also pressurized and shrinks accordingly. During flushing, the compressed air inside of the diaphragm pushes the water into the bowl at a flow rate which is significantly higher than a tank style gravity-flow toilet. This system requires slightly less water than a gravity-flow toilet. Pressure-assist toilets are sometimes found in both private (single, multiple and lodging) bathrooms as well as light commercial installations (such as offices). They seldom clog, but the pressurized tanks require replacement about once every 10 years. They also tend to be noisier - a concern for residential settings. The inner bowl stays cleaner (in appearance) than gravity counterparts because of the larger water surface area and the toilet's forceful flush. Newer toilets from several companies such as Kohler that are pressure-assisted use 1.4 US gallons (5.3 l) to 1.1 US gallons (4.2 l) per flush.

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Whether the "flushometer" toilet is truly a "tank type" toilet is open to debate. You learn something new everyday. What surprised me was how old the flush toilet is: circa 26th century BC. I wonder how many times toilets have been flushed since then?

Reply to
Robert Green

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

Reply to
Jeff Thies

And a new job category is created: Commode customizing toilet tuner!

-- Bobby G.

Reply to
Robert Green

Yes. But it's a shitty job!

Jeff

Reply to
Jeff Thies

e:

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!

Reply to
Bob Villa

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

Reply to
Jeff Thies

ge

We not taking about depth of water in the tank...the question was the

6 ft high tanks adding some great amount of pressure to the flush.
Reply to
Bob Villa

Very interesting webpage. I may have told this story before, but there are a lot of new people here, and I have questions this time.

In NYC I read or was told that every building above 6 or 8? stories had to have a water tank on the roof so that there would be adequate water pressure. Often you can see the tank but often they build simple walls around it. Sometimes the tanks are inside the top floor. Tanks are expensive iiuc because the roof has to be made strong enough to support them. (So a lot of buildings were/are? built just shy of the tank requirement height.) I've always wondered about this since NY, Brooklyn, and the Bronx** at least have hills, and I would think the absolute height of the building would be more important than the height relative to the street it's on. ??

**Staten Island has hills but not many tall buildings.

Buildings four stories or less can use normal water pressure. Not sure what determines the water pressure. The opening of the water tunnels from the Catskill mountains are much higher than 80 feet, I think, so it must be something inside NYC. ??

An inordinately large number of buildings are 6 stories. Few are 5 because the water requirements for 5 are the same as for 6, and many are only 6 because I think at 7 stories is when the water requirements increase) Buildings more than 4 stories and less than the height that requires a roof tank have to have two pumps and a water storage/ transit tank. One pump pumps the water into the tank against air pressure from the air in the tank. The second pump adds air to the tank, to replace that which is gradually absorbed by the water. In normal circumstances the air pump would only run once every 3 to 8 days, for maybe 15 minutes or an hour. It was automatic too, although I don't remember what turned it on.

I don't know if any tanks have rubber bladders. I sort of think not, but certainly the book I read didn't illustrate one and my building built in 1930 didn't have one.

My landlord was an immigrant from a fairly poor country in Europe. Or at least he wasn't very knowledgable about stuff. He became a "plumber" when there was a big demand for them in NYC when landlords were no longer allowed to burn trash in furnaces not designed to do that, and uncompacted trash could not be thrown away by apartment buildings above a certain size. The trash compactors were water powered, so he became a "plumber".

I'll give him credit that he wasnt' content to remain a plumber. By the time I met him, he owned 3 or 4 buildings small to medium sized apartment buildings, all but ours almost a slum, partly because he was the landlord. Left unchecked, he might have turned our building into a slum too, but there were too many tenants who could stop him. He lived in Long Beach, Long Island, a fairly small area but one with poor, middle, and almost rich neighborhoods. I didn't know and didn't want to know which he lived in, because I didn't want his apparent economic situation to influence my attitude towards him. I wanted it to be just legal and contractual.

But most of the tenants didn't know about the water situation** and only those on the 6th floor of the 6-story building really cared, plus a few on the 5th floor (mine worked pretty well really, but once in a while I had to flush two or three times. Mostly it annoyed me that he didn't know how to do things right. Oh, and when I was taking a shower and someone flushed the toilet, the shower became scarily hot. I think that wouldn't have happened if there had been local air pressure to boost the cold water flow. I switched to baths because of this.)

Anyhow, I think I once turned the air pump on and it seemed to be working. I think he didn't understand what the air pump was for so afaik he never used it -- the switch was always off -- and he had to run the water pump all the time -- the switch was never on automatic. So it ended up net-costing him money for electricity I think. I photocopied a page from the book I mentioned and sent it to him with a note, but I never heard back and I don't think it sank in.

**I only knew about the water because I spent time wandering around the big basement and looking at everything. There was no stairway, except outside, but the basement used to be available to everyone via the elevators. Someone must have done something to annoy him there, and when he put an electric-key-lock on the button that took the elevator to the basement, I waited until the middle of the night, took out the four big brass screws that held the brass control panel escutcheon in place, and attached some lamp cord to each side of the key switch, then ran the wire to just under the edge of the plate when I put it back on. It wasn't visible unless your eye was below 40 inches, and even then it wasn't really noticeable. It stayed this way for years, until some time after I moved out. I wonder if Alex figured out who put it there!

The floor-button-current was low-voltage and after I did this, I could hold a quarter or anything metal to the end of the lamp cord and bypass the key-switch, and go to the basement. I didn't steal anything or do anything bad. Mostly I needed this in case a fuse blew in the middle of the night -- this happend fairly often since the 3-bedroom apartment had only two fuses, both 15 amps, and both fed from a 20-amp fuse in the basment. Now I'm sure this would be a violation of code, but I think it was grandfathered in buildings of the era of mine. Anyhow, the fuse in the basement blew more often than the ones in the apartment, and I didn't want to wake the super or bother him after

5PM. I used to go down there to explore too.

If anyone asks, I'll tell you about my exploration of the furnace room, a story in itself.

Reply to
mm

So are you saying that the high tank doesn't help? Like Bob, I'm not sure. If not, why did they use it? Why did the drug dealers buy them?

I used to live upstairs from a pipe organ tuner. I should tell him about this new opportunity.

Reply to
mm

Pressure that would show itself in the speed of the water swirling in the tank. Seems to me it's like trying to wash the grass cuttings off the driveway with a garden hose at full blast, versus one whose pressure is cut because the spigot opening is 3/4 closed.

We can get by with low tanks and low pressure because the toilets are better designed, and don't usually need the greater pressure of the higher tanks, isn't that it?

Reply to
mm

I see your point.

It would seem to me that the initial pressure would be just of the depth of the tank, your point. Your point also about having the valve at the bottom of the pipe, which I don't believe they ever were.

Jeff

Reply to
Jeff Thies

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