Flow sensor to detect broken pipe


#1

Continuing the discussion from Flow sensor low flow integration?:

I think there is an opportunity here to detect and shut off the water flow if a leak is detected. One way it could work is via a learning/monitor program. A user installs a flow sensor and tells the Rachio app enable shutoff if a leak is suspected. The Rachio monitors the next run of that sprinkler line and samples the flow measurement several times. This allows it to generate a range expected flow. Then when the system runs in the future Rachio compares the current flow to the expected range and if it exceeds it by a specified factor (determined by testing some real systems) then it shuts off the water and notifies the user.

One problem with flow meters is they are currently expensive. A single flow meter could be installed upstream of all the irrigation control valves and then the Rachio app could be told which flow meter belongs to which sprinkler lines. Of course if you have separate systems in the front and back yards this won’t work so well since you’d still need 2 flow meters.

Which brings up another suggestion. A flow meter integrated into an irrigation control valve would bring the cost down. I don’t know if Rachio has approached any of the companies about producing such a model but it might be a conversation worth having.


#2

And incidentally this is based on a break I recently had in a line. I schedule the watering to run in the morning before the wind picks up, and it was fortunate I didn’t have the radio on which would have masked sounds. I heard the water running in the pipe going under my house to the sprinklers in the backyard and I thought “gee, that sounds a lot louder than usual; maybe I should take a peek out back and make sure everything is ok”. Water welling out of the ground told me things probably weren’t ok :confounded:


#3

Sorry to hear about the leak! Love the ideas around flow sensors. We’re very interested in flow and hope to best integrate flow data in the future.


#4

I also want to voice support for broken pipe detection. In fact, it’s the only reason I’ve upgraded to the Gen2. I have a lot of drip irrigation zones, so they tend to run for longer periods than a conventional lawn grass zone. So a broken pipe can waste huge amounts of water and be relatively ‘hidden’. About 2 years ago I had a $500 bill one month due to a broken pipe. To be most effective, we need the ability to set a ‘high flow limit’ per zone combined with an automatic zone disable and alert notification. Conversely, a ‘low flow limit’ notification is also useful to detect a failed solenoid, etc., before my shrubs and trees start turning brown.

I have owned a system by a Rachio competitor that incorporates these features. I don’t know if it’s considered appropriate to name the specific competitor’s controller in this forum, but I will be happy to give details if that’s acceptable. And while I like the extra safety provided by this competitor’s flow monitoring, in the end, the other basic features of the competitor’s controller were unreliable. And remote communication was terrible. So based on my experience with a Rachio Gen1 for my front yard, I’ve replaced this competitor’s system in my back yard. So I’m very anxious to see some broken pipe detection in Rachio. That that will seal the deal for me. I definitely like Rachio’s interfaces MUCH better than this competitor’s system that I have also been using for the last 2 years.


#5

I have worked with another vendors system (Smarlink by Weathermatic) at another site. Their approach is simple and effective. It records current (last run) average (over multiple current) flow for each zone. It allows the user to set a max and min flow for each zone which can be based on the average flow. If either are exceeded it sends a flow alert to the user and has the ability to close the master valve.


#6

I found an open source project that uses a magnetometer to monitor the spinning of the home water meter. Project webpage is https://hackaday.io/project/1460-remote-water-consumption-display

This is potentially useful but not perfect since it monitors all water use by the house. If someone is running the washing machine or taking a shower then the total water flow would be higher than that used by the irrigation system, falsely indicating a leak.

But since Rachio is a hardware company this project shows a low-cost way you could build a flow meter. A small piece of pipe placed inline with the water supply to the irrigation controllers in a given location (eg. front yard, back yard) with a spinning wheel inside it could generate a signal that the magnetometer detects. Power to run the magnetometer and associated circuitry could come from the 24V sent to the irrigation controllers when they are on. And instead of using wireless (which may have distance and interference problems) the detected clicks of the spinning wheel could be sent back to the Rachio controller by AC coupling the signal onto the 24V control line.

This system could monitor for leaks and, as suggested by @sdxeriscape, it could also detect when a sprinkler channel fails to turn on.


#7

I too like this idea of Rachio controlling a shutoff feature detected by the flow sensor in the event a pipe breaks or solenoid sticks open. Totally would buy into this for piece of mind, like if not home, on vacation and so on.


#8

I think along with broken lines, the number one reason for flow alerts would be pump protection. There are ways to do this outside of a flow meter, but they are costly as well. Integrating this feature would be a big plus for anyone that uses a pump for their irrigation system.


#9

My suggestion for implementation is to include another set of contact closure in a Gen 3 product. This contact closure set would close (or open) if a flow sensor sensed an extraordinarily long cycle. The limit value could be a Rachio setting input.

This is much like today where we have a contact closure that mirrors zone ‘on’ time, with the closure intended for pump usage.

Best regards,

Bill


#10

I have installed a flow sensor and while I am very happy to have actual total flow across all zones I am eagerly awaiting further integration of the sensor and the additional data it can provide including total flow (volume) by zone and notifications for high/low total flow (volume) by zone. Additional data points will provide us with more information about where we use the majority of our water and I expect this ‘new’ information will drive real changes in how we choose to allocate our monthly water ‘budget’. It’s one thing to inherently understand that our lawns are sucking-up the majority of our water allowance but it will be impactful (and undeniable!) to see hard data that shows that our actual usage on our lawns (for instance) is @ 80%, shrubs @ 10%, and our vegetable gardens @ 10%. This information may stoke some to reduce or remove their front lawn and install a beautiful edible garden. Changing our baselines will save more water over time vs. the incremental savings we get from skipped rain days.

I’m also curious if know if there will be a way to capture the volume of water that I use from the hose. I have a couple of hoses downstream of the flow sensor. They both branch off of the main line and thus are not associated with any particular control valve/zone. I typically run my hose when I am not watering through any of the zones. I don’t do this intentionally, it just works out that way b/c my zone schedules are mostly early-AM and if/when I use the hose it’s generally after work M-F or mid-AM S&Su. In my case it may be relatively simple to capture hose volume as TOTAL VOLUME - SUM(All Zones). This assumes that Rachio is able to monitor and collecting data all the time! For those that hose water while their zones are running, they will need to understand their zone volumes may be skewed. If hose volume is not captured then many of us may develop a bad habit of ‘cheating’ by supplementing with hose water while celebrating our achievements of a low monthly usage! We’re only human!..