Home Water Flow Rate

Get it changed, then.

...because it's cheaper than changing the wife... <ducks to avoid thrown objects>

Though I've never measured it, I doubt that a 5-gallon pail holds exactly 5 gallons. Your 5.45 gallons doesn't sound unreasonable for up to the brim. Furthermore, your toilet probably wasn't calibrated .

The flow rate can vary widely depending on pipe size, length, number of elbows and other fittings.....

But as a simple figure, 5- 10 USGPM through a 5/8 meter sounds quite reasonable. At the 19.88 gpm mark, that thing must have been whistling!!

To make an accurate check you need to weigh the water and correlate that to your meter. Do it at several different flow settings; use the 5 gallon bucket and fill it up. Weigh the water & divide the pounds by 8.345 to get the actual gallons (don't forget the tare weight of the bucket).

It sounds like you have two issues: meter accuracy and flow rate. I would request from the utility that the meter be checked for calibration and replaced if necessary, showing them your figures. As for the flow rate, the biggest variable I've seen is time of day, and I set my grass watering timer for early AM for that reason. I live in town so I don't know if there is the same effect in the country. If your pressure is consistently low, it could be due to mineral deposits in the mains.

...and for highest accuracy, remember the density of water varies with temperature. Use a set of Steam Tables to establish the density applicable to the installation in question.

Flow rate is the result of line ID and pressure.

Over reading of volume indicates higher than normal pressure for your flow meter.

Get the meter checked and replaced/recalibrated.

I'm fully convinced that the meter needs replacing.

I'm wanting to load up my basket of "Facts and Data" for when I approach them about replacing the meter (and refunding for over charges).

The water pressure drop doesn't concern me. I expect it to drop when the irrigation system is on. Even the drop to 40 psig when filling the 5.45 gallon bucket is not surprising.

What is surprising is the calculated flow rate of >19 gpm (at a line pressure of 20 psig) whenever either of two zones is turned on. I have a hard time accepting that a home system can deliver 19 gpm even under the best of circumstances.

I have looked around quite a bit, but I have not found an answer to this one last question: For a typical home (3 bedroom, 1 1/2 bath, etc.) what is the maximum flow rate that the water line can deliver?

Fill that 5 gallon bucket and tme it with a stop watch. Do that 3 or 4 times and average the results.

There's some real data for you.

Our pressure fluctuates depending on the time of day.

44.9 seconds, each time. ~6.8 gpm.

There's your smoking water bucket.

Would the fact that your 5-gallon bucket could hold up to 5.75 gallons change your mind, or did you calibrate the bucket?

Take an empty 1 gallon milk jug and rinse it out.

The volume of these containers is constantly verified by the state.

Note the level in the jug of new unopened milk for comparison.

Dump 5 of these containers full of water into a five gallon bucket and mark the level in the bucket.

You now have a fairly accurate,but not exactly precise 5 gallon reference.

Get as many measurements as possible,and average them together.

Make a note of all measurements to present to the utility.

It should be enough to convince yourself of the problem or lack thereof.

As for the toilet,take that flush rating with a grain of salt.It is adjustable and may be out of tolerance.

There is no standard flow for a house,because there are too many variables to consider.

The pressure of the system at the time of measurement,length of piping,external and intenal,size of piping,types of valves in system,how many fittings,and of what type...the list goes on.

There is a standard AVERAGE per-person usage,but that will not provide the

information you require.

The water meters are usually very accurate,being a multi jet type,coupled to a mechanical movement by a magnetic coupling.

Newer smart water meters are an exception ,and may generate pulses for a digital counter,using various technologies,such as vortex shedding,mass flow,etc.

As a general rule,meters tend to read lower as they age,not higher.

Be careful what you wish for.

GA

Liked your post.

"Note the level in the jug of new unopened milk for comparison."

The level of a new unopened 1 gallon milk bottle should be 'right to the top of the neck,' that's now the filling stations work, pump the bottle until they just start to overflow, then cap 'em and ship 'em.

the air bubble is from imperfections in the system, and I believe there are regulations about the fill, something like '1 gallon +/- 1 ounce' which is a variation of +/- 1/128 of the stated value.

But if you want to be REALLY sure, you can always fill the jug from a calibrated source (aka, use measuring cups marked for fluid ounces) and mark the point where it hits 128 ounces/1 gallon.Might seem like overkill, but when you're fighting a public utility about overcharges/faulty equipment, you need all the ammo you can get to plow through their bureaucratic obstruction.

There probably are still some old style fillers out there,that adjust level by adding or subtracting washers from the fill stem,but that is 1950's technology.

The newer ones fill by weight.Each empty container goes onto a plate that subtracts the tare weight,and as the filler rotates,it is filled to a programmed weight,to a very high precision.

Variations of the bottle can cause errors if using level, but not weight.

It starts filling at a high flow rate,and decreases to a slow rate near end of

cycle,tapering off to zero to finish the fill.

All the while the bottle is moving around the turntable of the filler,at a rate of 200+ per minute

US Bottlers brand can guarantee +or _ 1 gram.fill weight.

Don't bother with proving to the water company what the error is. An error in the meter can be off either way, at their loss or at your loss. They certainly would want to replace it if they were under reading the water that they were selling to you. They also usually have a schedule for replacing the meters periodically. My supplier replaces them every 10 years. They recalibrate them and put them back in service as needed. It is not an unusual thing for the meters to read wrong, they don't want it anymore than you do.

Just ask them to replace the meter because you suspect the meter is reading wrong. Tell them it is reading high and they will put it on their schedule. Tell them it is reading low and they will be out there right away.

A few people I know of have been billed for a full capacity of the meter (it went around the complete scale to near the original reading) and the water company wanted them to pay thousands of dollars because the meters were running extremely high and inaccurate. A new meter is your right as their customer. Besides all this the water company representative probably wouldn't understand any of your "scientific" calculations and experiments to prove the inaccuracy of the meter.

There are many horror stories about utilities billing customers. Get this on your "hot" list and get it taken care of as quick as possible. Don't forget they are the ones with the curb valve and the "T" handle. They can cut your water off at their whim but you can't turn it on at your whim.

Good Luck, Old Salt

Is that it? A curb valve and T handle to turn it? I can't see why you can't turn it back on yourself.

They physically take the meters away here....dang!

Forget to pay your bill here and a crew turns up to get the money++ or start digging.

There are two primary set-ups in the USA. A surface valve box and a buried valve box.

In warm areas where it doesn't freeze they simply install a cast iron or plastic box flush with the ground surface. The shut-off valve is located there. It the water company wants to shut you off all they have to do is open the cover, shut the valve off and put a padlock on it.

In areas where the ground may freeze or there is heavy frost a buried valve box is used. The bottom of the valve box is installed (it has a 1/4 turn straight top valve stem as a handle), install the curb valve below grade, install the valve box extension and place a cover on the extension. This is all installed to leave the top at grade. The "T" handle to turn the valve is anywhere from 2ft to 12ft depending upon the burial depth.

Completed Set-up

Components listed at: http://catalog.muellercompany.com/Catalog/Complete-Curb-Valve-and-Box-Catalog-Section-7-Best-for-BROWSING/647

To shut you down they remove the cap from the valve box extension, use the "T" handle/curb box key to close the valve and put the cover back on. I have been told by the service personnel that to shut off/open the valves that they do not announce their arrival in order to prevent being beat up and assaulted. They don't carry cash or accept any type of payment to avoid being robbed and/or assaulted. They hang a tag on the front door to let you know they were there and what they did. To discuss anything you must call the business office.

Most people don't have the curb box key so they can't open the valve.

Good Luck, Old Salt

If the meter is at ground level in a box, in the basement or anywhere else that is accessible make up an appropriate "Spool Piece" to take the place of the meter. This is just a piece of pipe cut to the appropriate length with ends identical to that of the meter. Many meters have pipe threads on the meter which end pieces are connected to. (Easiest if done with an old meter that parts can be salvaged from) Take these off and along with a combination of fittings and pipe (preferably "L" type copper, threaded brass or bronze, or stainless steel) and assemble them with pipe, a valve and, if possible, a union. Install this where the meter was, open your valve and enjoy a shower.

We used it in chem manufacturing while working on meters or other instrumentation and could operate by other types of measurements.

Anyone worrying about the pressure or rate of water when the main question is of the accuracy of the meter, is simply wasting time....as it simply should not matter how fast or slow the water is delivered, the meter should still measure within the correct tolerance(s).

In fact, the meter should be tested with high, middle and low flow rate as well! eventually, once the meter has proved to be basically accurate! But it should not make a difference.

The best way to start is to measure exactly how much water is delivered when the meter says its say exactly 1 gallon.

This can be checked simply using milk containers as HiTekRedneck suggested, or using an accurate scales and weighing the water, removing the weight of the bucket/container of course....

Uncalibrated toilets cannot be used in such work unless you have a method of measuring the volume of water delivered.....and who calibrates their toilette??? Companies tell you one thing, when careful checking demonstrates something quite different, car fuel consumption comes to mind!!! Do they EVER quote a higher fuel consumption than usual? NEVER EVER!!!

Although temperature does change the volume/density of water, I do not think that the temperature as it comes from the mains will change it enough to be worth talking about....which this graph appears to support, assuming I am reading it correctly!!:-

Borrowed from here:-

water-specific-volume-weight

"Close enough for Government work", as an American friend of mine always says!!!

Although if the water is significantly warmed before passing through the meter, and the meter is only accurate for a far lower temperature, and large volumes of water are the norm, well it may be a small part of the problem.......

I do feel that an accurate water meter is a given and if the one you have proves to be inaccurate, the company should not only change the meter out (check again the new meter!!), but also offer restitution, especially if you are a large water user as your post suggests to me....

My main worries are that testing a single gallon, might not really demonstrate the error accurately enough, but its certainly a good start....

Best of luck.

Hi AG,

Nice post. You elucidated some of the things I was saying - more detail than I though. It seems that the OP doesn't get back here that often. Anyway, if you are doing bucket-and-stopwatch measurements, you had better know the volume of your bucket! Using a larger volume will increase accuracy - more so as the flow rate increases. I would have had this figured out long before now.

:-)

I think most of here would. Neither would I be posting before "knowing" a lot more, but that is just me I guess.....Its a simple exercise really....

Have a great day.

Based on my 5-gallon bucket calibration (volume, time and pressure) of 6.67 gpm, I calculated that the flow rate for the worst of my irrigation lines should be ~9.39 gpm rather that the 19.88 gpm that the water meter "suggests".

Even without using a calibrated bucket to get there, this calculated value of 9.39 gpm is probably within 20% of the actual flow rate.

The local water utility is coming by Wednesday afternoon to remove the meter for a calibration check.

They've invited me to attend.

"Anyone worrying about the pressure or rate of water when the main question is of the accuracy of the meter, is simply wasting time"

Unless the pipe meter ID has been reduced by Ca deposits.

The water meter, if correctly calibrated, designed and built, should measure water usage accurately (within standard tolerances) from a small flow, to a full flow, at any one of the range of pressures that it covers.

If it doesn't, then it needs to be replaced.

In hard water areas (which the water supplier would be expected to know about!), knowing the optimal time to replace them before such deposits cause possible problems is important.....

I personally feel (guessing only) that such deposits as you mentioned, might possibly reduce the amount of water measured, rather than increase it over actual/real, but I could be wrong on that point!!

Here we have meters with a tiny propeller driving the counter wheels.....but its possible that other designs work quite differently and deposit buildup also affects the readings differently....!

Here they get replaced about every 5 years or so because of hard water deposits, "slowing them down".

Velocity.