Toilets: tanks vs. pipes

Factual Questions
1

Here in the northeast USA, we have basically two kinds of flush toilets, at least to this non-plumber.

In one, there is a tank of water which provides a convenient place to lean one’s body while sitting. Flushing the toilet empties this tank into the bowl to wash everything away, and then it refills for the next user.

In the other, there is no tank at all, and leaning back is not comfortable. Flushing simply opens a valve which allows a preset amount of water out of the building pipes and into the bowl. The valve then closes on its own. I can see several advantages to this setup: It seems like a less complicated contraption, with fewer moving parts, and fewer parts in general, which ought to make for a cheaper price. Also, there is no time delay waiting for the tank to refill, and big messes can be flushed repeatedly, in much less time.

My question is this:

From what I have seen, private homes use the tank type exclusively almost without exception, and commercial buildings (offices, stores, factories) use the pipe-and-valve type the great majority of the time (the exceptions tend to be in the smaller businesses).

Why the discrepancy? I would think it quite simple to get rid of the tank from home toilets. Move the valve from the back to the side, and the whole toilet could be moved a little closer to the wall, making a roomier bathroom and a smooth wall to lean against. The toilet would be cheaper than what we have now, and no one will need to ever replace the rubber floater stuff inside the tank.

Any ideas? The only thing I can think of is that these pipe-valve things are too dangerous or tricky to install except in buildings which have a full-time maintenance person. Can that be it?

2

Commercial buildings have pipes with larger diameters that can deliver adequate water pressure for a flush. Homes tend to have smaller pipes so their toilets need a reservoir to hold water that can be delivered fast enough for a flush. So you would need to upgrade the plumbing in most homes to lose that tank.

3

It seems the water tank delivers about 0.5 gallons / second for 10 or 12 seconds. That’s 30 GPM

4

Pederabo is right on the water pressure being the issue. At 30 gpm 1" copper pipe loses about 51.6 feet of head pressure per 100 feet of pipe. 3/4" pipe has a pressure drop of over 100ft/100ft. Fittings like valves, elbows and tees add lots more pressure drops. Water pressure delivered at the street should be about 90 PSIg, and lower than that going through your pressure regulator. In a normal two story house you would have to put in a booster pump just to flush on the second floor. You would also have to upgrade all you fixtures to handle the higher pressures. Homes aren’t set up to handle the flow. Also there is no way you could flush while the dishwasher, clotheswasher, sprinklers, shower, etc. were on.

The tankless toilets aren’t all that great, either. When they fail you can get a whole lot of water either down the drain or onto the floor really quick, and if no one is there to shut it off it you are screwed. If you went away for a week and if it failed your water bill (in So. Cal.) could exceed your house payment.

Do what everyone else does. Go to Tiajuana and get a nice old style toilet that actually flushes - the low flows suck.

5

>> the low flows suck

I’m with you on this one. That’s what happens when the government start legislating this kind of stuff.

While we are on the topic of toilets I would make the observation that American toilets seem to clog more often than the European ones I have used. I have noticed the stack pipe here is 4" while I think in Europe they are 5".

It seems I am always clogging the toilet (A girlfriend of mine some time ago made the comment that I must “shit square”). Or maybe I should not eat so much fiber.

Anyway, Using the toilet for me has become an adventure. When I flush I have to keep my sight on the bowl and be ready to lift the cover of the tank and closer the flapper valve if the bowl begins to overflow.

6

>> the low flows suck

Well, most but not all. About three years back I had to replace a “full flow” toilet with a “low Flow”. I did some research and discovered what are called Pressure Assisted or PA toilets. This has a 1.6 Gal pressure tank in the ceramic tank. This holds water under pressure which is released into the bowl when the lever is tripped. It’s a little loud, but that stuff is gone!
TOLO toilets are also supposed to be some of the best in a gravity flush model.

GaryM

7

I think there’s another reason - toilets with tanks are not good for commercial buildings because it takes a minute or two for the tank to fill up. In a home it’s not as big a problem, because you rarely have to use the toilet right after someone else did.

8

former plumbing warehouse employee here…

Perderabo is right about pipe size, and Engineer Don is, well, an engineer, and knows his stuff. It’s all related - pipe size, pressure drops, number of turns in a pipe, the height that a column of water will rise without needing booster pumps, etc.

Modern day low flow residential toilets will deliver approximately 1.5 gallons of water. The shape of the toilet intake and rim deliver the familiar vortex of water in a more efficient flush than the good old 11 gallon crapper. If you dumped a bucket of water in the bowl at an angle, you would get the same effect. Typical residential water pressures do not exceed 50 psi, and with water drops from other sources, street pressure alone would not be adequate to empty the bowl.

Commercial bulidings have larger diameter pipes, and combinations of water pumps and tanks at different levels, depending on how tall the building is. The pressure is great enough to keep the spring valve and/or vacuum actuators inside of your typical flush valve open long enough to work.

Stack size refers to the diameter of the waste pipe which your bowl is attached to, generally 4". Most clogs occur within the outlet of the toilet itself, which at a minimum must be able to pass a wooden ball of 2 1/4" diameter. (someone actually tests this)

Sailor, I, too, have often wondered just what in hell I ate the night before. The plunger is quite a handy tool at my house, and there’s nothing quite like running late for work and then having to slosh up a big bowl of poop d’jour. Oddly enough, Mrs. Wolf never seems to have this problem…until the other day. HA! I am not the only circus freak! But why does this happen? Surely, with an outlet diameter of 2 1/4" (uh, that’s on the toilet), nothing produced by a mere human could produce such a blockage as to prevent a toilet from flushing. Certainly not without an epidural.

What could be the cause? Perhaps the flushing action folds everything up and turns it sideways, creating a little dam halfway down the chute. Then again, maybe it’s just gordidas. :smiley:

Besides, if houses didn’t have tanks, no one would ever be able to unleash that most feared of party pranks, yes, the dreaded upper-decker.

9

>>>>In a home it’s not as big a problem, because you rarely have to use the toilet right after someone else did.<<<

Obviously you didn’t come from a large family living in a one bath house!

The “tankless” models are a lot harder to work on too,Sloan type valves stick alot,parts wear out,diaphragms rupture…etc.

10

Dire Wolf says:

Come on, don’t leave us hanging…what’s the “dreaded upper-decker?” Sounds too good to pass up.

11

I lived in an apartment building that used to be a hotel and it had the pipe-style toilets - I loved those things, never got stopped up, which is a problem for me sometimes, especially with these new toilets that can barely flush a single wad of toilet paper.

12

You really want to know???

OK. Don’t say I didn’t warn you :stuck_out_tongue:
Say you’re at a party with lots of people, and maybe you don’t especially care for the host. Maybe you’re in a rambunctious mood. Maybe you’re just really drunk and not in control of your actions. Whatever your motive, one thing is for certain: you’ve gotta take a shit. Locate the nearest bathroom, lock the door, and then take the lid off the toilet tank, being ever so careful to quietly remove any sundry tank-top adornments first. Then…you guessed it, buddy…you take a dump in the tank :eek:

Quietly replace the tank-top, and carefully return any bottles, spray cans, or other items to their original position. You slip out and blend in seamlessly with the party festivities, smiling a secret little smile :slight_smile:

No one will notice anything, not at first. But by the next day, after everyone is long gone, your little surprise will slowly start to distinkgregate, er, disintegrate. Carefully metered doses of choad will be dispensed into the bowl with every flush. After a couple of days the bathroom air will be permeated with a combination of sewer gas and roadkill, leaving the homeowner to wonder who’s sick, and just what in hell do they have!!

If they are smart enough, they will think to check the tank. When they lift off that lid, what a surprise they will have!!! Big Laffs :smiley: Perhaps a look of horror or disgust will cross their face. They will have no choice but to ladle the offending material out of the upper deck and into the bowl.

Alternative number 2 no pun intended
Note: Your host must have a cat!!!
Most people keep the litter box in a bathroom. So…you guessed it again…carve out a little furrow and deposit your offering. Cover it up like a good cat would, and return to the party. By the next day, they will be taking the cat to the vet :wink:

13

Note to Self: Scratch Dire Wolf off party guest list!

14

Gasp!:eek: Shock!:frowning: Disbelief!:confused:
Fear Itself, I thought we were pals? I would never do such a thing! Well, probably not. Alright, I might look inside your medicine cabinet, but that’s it, I swear! Besides, I don’t shit. I will simply explode when I turn 50.

[sup]Disclaimer: Dire Wolf does not condone the above stated shenanigans. For entertainment purposes only. Any resemblance to characters real or imagined is purely coincidental. Contrary to what some of you people must surely think, Dire Wolf really isn’t the sick, twisted individual that he may appear to be, and would never shit in
your toilet tank, or for that matter, your hat. He is a regular guy (so just don’t invite me to any parties in the morning.)