Remote detection of water flow through a pipe

BR-549

Joined Sep 22, 2013
4,928
From what I can gather from this thread is that you already have the best leak detector there is.......a pressure gauge.

This will only tell you that you have a leak.....not what kind or the location. It might be an internal leak...i.e....check valve or isolation valve. Or it could be an external leak.

So.....all you have to do is monitor the RATE of pressure. And the only rate that you are interested in...........is a small, slow rate window.

To be able to detect a leak......you must start with a non leaking system. Not sure if you can do it with $50.

You will need an analog pressure sensor, and small processor board and an annunciator.

The strategy is to measure the pressure at a set interval......and measure the difference from the last measurement. This strategy will NOT give you indication of breaks or streams......but will detect drips and leaks.

The first thing to determine is the interval. With all faucets turn off and well pump kicked off......adjust a faucet flow for a toothpick stream. By the way...use a sink faucet, not a drain valve.

Start off with a second of interval. Take a pressure measurement every second for one minute and see if you can see a pressure change. Let's say that you can see a pressure change in 5 sec. with that toothpick flow.
We want to ignore any change greater than that flow. We only want to alarm on a flow that is less than toothpick but greater than zero flow. AND...AND only within TEN seconds. We double the interval to gain resolution of the small change. All no flows and high flows are ignored.

This is only a strategy and I used arbitrary numbers. Your system's capacities will determine the numbers. I hope you get my drift. In the real world you would end up with three sets of numbers. A small set of zero flow numbers.......a small range of alarm flow numbers and a set of large flow ignored numbers. These sets are referenced to the time interval.

The cheapest way to determine a leak is a pressure gauge and a clock.

One can customize and carry this out much farther if you want. One could easily recognize a toilet flush. Or a washing/dish washing machine cycle...or an ice maker cycle. And of course you could calibrate the whole thing.
 

Tonyr1084

Joined Sep 24, 2015
7,852
I don't think a pressure gauge will serve the purpose. Unless you have an absolutely closed system - no water entering, no water exiting, the gauge could only detect a leak if the supply of water is not being replenished. In other words, pressure alone will be subject to line pressures as well as temperature variations. Back in high school we made "Reverse Thermometers" out of a plastic bottle, red died water and the ink straw from an old pen. Having washed out the straw, you could then see the red water in the tube. As the room warmed up the plastic bottle expanded, creating a larger cavity for the water, and the level in the straw would go down (not up). When cooled, the plastic bottle would contract and squeeze red water up the tube. So pressure variations are not going to be able to detect a leak; not unless there was no continuous supply and no temperature variations.

I'm following this thread because it's becoming very interesting. Exactly how I would detect a leak the size of a pin hole at 80 PSI ? ? ? Not that I have a purpose for it, but I find this interesting.

The goal is to keep this cheap but workable. The earlier drawing I posted could detect water flow far greater than a leak but would not likely detect such a small pin-hole leak. Maybe I'd wrap the pipe in cotton infused with salt and run two stainless steel wires down the length. If a leak occurred within that section the cotton and salt would become conductive once wet, and you'd get an alarm. However, once a leak has been detected the system is useless because there would be no good way to dry out the cotton other than to let it air dry. Humidity could also adversely affect the effectiveness of such a situation.

To the thread starter: Are you trying to detect a leak within a large system or in a small area? Knowing more about your end goal would help us help you. I've seen some pretty interesting approaches so far and I'm hopeful someone can give you the answer you seek.
 

Thread Starter

Ferdmonster

Joined Apr 22, 2017
13
I don't think a pressure gauge will serve the purpose. Unless you have an absolutely closed system - no water entering, no water exiting, the gauge could only detect a leak if the supply of water is not being replenished. In other words, pressure alone will be subject to line pressures as well as temperature variations. Back in high school we made "Reverse Thermometers" out of a plastic bottle, red died water and the ink straw from an old pen. Having washed out the straw, you could then see the red water in the tube. As the room warmed up the plastic bottle expanded, creating a larger cavity for the water, and the level in the straw would go down (not up). When cooled, the plastic bottle would contract and squeeze red water up the tube. So pressure variations are not going to be able to detect a leak; not unless there was no continuous supply and no temperature variations.

I'm following this thread because it's becoming very interesting. Exactly how I would detect a leak the size of a pin hole at 80 PSI ? ? ? Not that I have a purpose for it, but I find this interesting.

The goal is to keep this cheap but workable. The earlier drawing I posted could detect water flow far greater than a leak but would not likely detect such a small pin-hole leak. Maybe I'd wrap the pipe in cotton infused with salt and run two stainless steel wires down the length. If a leak occurred within that section the cotton and salt would become conductive once wet, and you'd get an alarm. However, once a leak has been detected the system is useless because there would be no good way to dry out the cotton other than to let it air dry. Humidity could also adversely affect the effectiveness of such a situation.

To the thread starter: Are you trying to detect a leak within a large system or in a small area? Knowing more about your end goal would help us help you. I've seen some pretty interesting approaches so far and I'm hopeful someone can give you the answer you seek.
Thank you for all the thought given to your reply. I really appreciate all you guys chiming in on this problem. Let me be a little more descriptive. The system is a home water supply system. The county meter is located about 1000 feet from my home. I have two separate irrigation systems branching from the main water line. In the past I have had leaks in my system that ran the bill over $1500 for one month. So my goal is to either find a reasonably priced water leak detection system or develop one myself so that I never run into this problem again. I want to be alerted preferably via cell phone for any leak whether large or small. I hope this draws a better picture of the problem I'm facing here.
 

Picbuster

Joined Dec 2, 2013
1,047
Thank you for all the thought given to your reply. I really appreciate all you guys chiming in on this problem. Let me be a little more descriptive. The system is a home water supply system. The county meter is located about 1000 feet from my home. I have two separate irrigation systems branching from the main water line. In the past I have had leaks in my system that ran the bill over $1500 for one month. So my goal is to either find a reasonably priced water leak detection system or develop one myself so that I never run into this problem again. I want to be alerted preferably via cell phone for any leak whether large or small. I hope this draws a better picture of the problem I'm facing here.
I do not know what type of water meter you have but most of the meters do have a pulse out option driving a contact.
One pulse per x volume and is depending on type of meter and installed option.
Picbuster
 

Thread Starter

Ferdmonster

Joined Apr 22, 2017
13
I do not know what type of water meter you have but most of the meters do have a pulse out option driving a contact.
One pulse per x volume and is depending on type of meter and installed option.
Picbuster
The only thing I know about my meter is that it is a mechanical digital readout with a small quarter-inch red triangle that rotates with any water flow. A tiny trickle makes it move very slowly. It's rotation rate is directly proportional to water flow rate.
 

AlbertHall

Joined Jun 4, 2014
12,344
It shouldn't be too difficult to put a reflective opto-sensor to detect the movement of that red triangle. That signal could run along a wire to the house, which could also supply the power, or the remote site could be battery powered and transmit the data to wherever. The remote site will need a fair bit power so connecting it with a wire or using a rechargeable battery and a solar panel to charge it would be recommended. The data could then be sent using bluetooth to the mobile phone but that is going to need a microcontroller of some sort.

That way you would know the water consumption at any time but you would have to decide, based on that consumption, whether there is a leak.
 

Thread Starter

Ferdmonster

Joined Apr 22, 2017
13
It shouldn't be too difficult to put a reflective opto-sensor to detect the movement of that red triangle. That signal could run along a wire to the house, which could also supply the power, or the remote site could be battery powered and transmit the data to wherever. The remote site will need a fair bit power so connecting it with a wire or using a rechargeable battery and a solar panel to charge it would be recommended. The data could then be sent using bluetooth to the mobile phone but that is going to need a microcontroller of some sort.

That way you would know the water consumption at any time but you would have to decide, based on that consumption, whether there is a leak.
Thank you Albert. I'll look into that.
 
Do you have web access to your water usage? Electric is done differently. I believe it's Zigbe with a cellular gateway and you have better access.

Another idea is to add another water meter in series, now that doesn't help you with the 1000 feet.

I THINK the way out water meter system operates is there is a battery and antenna in the basement which is designed to last about 10 years.
I THINK someone has to "drive by" and get the water info.

Where I used to work,we had no water meter,we got charged by the difference of two other meters.

There's a number of stuff on this http://www.flows.com/wifi-remote-water-meter-reading-system/ page that I haven't looked at, e.g. http://www.flows.com/wifi-remote-water-meter-reading-system/ You can always have an electric meter installed if there isn't one nearby like traffic lights do.

Now that I have a better description of the problem, I can help.
 

wayneh

Joined Sep 9, 2010
17,496
Thank you Albert. I'll look into that.
If you could manually detect a leak by standing at the meter and viewing the meter, I think you could consider just pointing a webcam at the meter. The complete solution would be a bit more than $50 but you could use off-the-shelf equipment and not spend time horsing around with a DIY solution.
 

BR-549

Joined Sep 22, 2013
4,928
Something's fishy about this thread. You have a verifiable problem that has cost you $1500. And from your post, will certainly happen again.

And you expect to solve it with $50.

Get your wallet out and buy a remotely controlled main water valve. And pay someone to install it for you.

You can monitor, control and alarm you at your house.

Surely you can claim a business expense or some such thing.

And I hope those two, thousand foot irrigation runs..........aren't 3/4 inch.
 

Thread Starter

Ferdmonster

Joined Apr 22, 2017
13
Something's fishy about this thread. You have a verifiable problem that has cost you $1500. And from your post, will certainly happen again.

And you expect to solve it with $50.

Get your wallet out and buy a remotely controlled main water valve. And pay someone to install it for you.

You can monitor, control and alarm you at your house.

Surely you can claim a business expense or some such thing.

And I hope those two, thousand foot irrigation runs..........aren't 3/4 inch.
Something's fishy about this thread. You have a verifiable problem that has cost you $1500. And from your post, will certainly happen again.

And you expect to solve it with $50.

Get your wallet out and buy a remotely controlled main water valve. And pay someone to install it for you.

You can monitor, control and alarm you at your house.

Surely you can claim a business expense or some such thing.

And I hope those two, thousand foot irrigation runs..........aren't 3/4 inch.
You're right BR, it does seem fishy and it would be if I were only thinking about myself. However there may be thousands of water customers in my county who could benefit from a device as outlined in my posts. Thanks for pointing out my error.
 
Never checked into it but I wounder if water leaks can be detected by ultrasonic like air can. Maybe in the water itself. Still probably wouldn't work- cost plus having to be detecting somewhere close in the area of the leak in the first place.
 

Thread Starter

Ferdmonster

Joined Apr 22, 2017
13
Never checked into it but I wounder if water leaks can be detected by ultrasonic like air can. Maybe in the water itself. Still probably wouldn't work- cost plus having to be detecting somewhere close in the area of the leak in the first place.
I don't know either neuhauser. Thanks!
 

cmartinez

Joined Jan 17, 2007
8,218
To be honest, I think that you should drop the $50 cost goal to your project, and focus on something more attainable. That goes too for the restriction on it's being non-invasive.

You lost far much more in the malfunction you've described. My take would be to build a small system with the pressure vessel that I previously described, and then gradually improve it by writing software and proper algorithms that could distinguish between a leak and normal consumption, and then enhance it with alarms and data logging until I'm satisfied with its performance.
 

crutschow

Joined Mar 14, 2008
34,280
I have an automatic master value in front of my other irrigation valves to remove the pressure and prevent them from leaking when off.
It's actuated by the irrigation timer (which has a pump output signal that's energized whenever any of the sprinkler stations are on).
What that be a possible solution for you?
 
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