TD;DR - Control city water flow; 1 1/4" input @ 65 GPM / 80 PSI without spending $1,500
I need to control water flow, simple on/off our our distillery. Accuracy of a few gallons in 500 is perfectly acceptable. Incoming water line is 1 1/4" copper. Max flow rate is 65 GPM @ 80 PSI. I need to be able to enter a volume (e.g. 530 gallons) and have the arduino open the valve, count ticks from sensor, and shut off flow when the entered volume has been reached. I can handle real-time display, etc, etc. Plan on using Yun to allow web-based control & monitoring.
A couple of head-scratchers into which I've run:
- 1 1/4" flow meter. I can't seem to locate one that's under $900
- Valve type. Typically this process takes under 15 minutes. Somewhat concrned about powering a solenoid for that long. I've no experience implementing and h-bridge in arduino that woudl be required for a latching solenoid
I have a reasonable budget for this project, just can't seem to find the correct pieces and parts.
I'd ask a local plumber for alternatives, and for possible legal requirements.
They do exist, really. Their 3' water meter with computer output is just RMB790 (or just over USD 120 - I guess that's your version of $ as you use typical US local units) can do 63 m3/hour, that's like three times the flow you ask for. This one took me just a few minutes to find.
The city water authorities get very nervous when you attach something to their pipes. They require licensed plumbers for certain types of jobs. Backflow is one of their main concerns. Your Arduino may be able to shut off the water in a way that pushes a small amount of contamination back into the city pipes. That can then affect their other customers.
$900 seems appropriate for a flow meter that size. You could use a smaller one with adapters.
Of course the one I linked to does not come with any certifications (but that wasn't asked for, either).
Indeed you may need to add a one way valve in the system as well if back flow is a concern.
For your valve: maybe use a motorised normal valve, not a solenoid. One that has to be turned to close. That would also allow you to slow down the flow gradually as you reach the required number, instead of having a pure on/off situation.
ebstauffer:
TD;DR - Control city water flow; 1 1/4" input @ 65 GPM / 80 PSI without spending $1,500
I need to control water flow, simple on/off our our distillery. Accuracy of a few gallons in 500 is perfectly acceptable. Incoming water line is 1 1/4" copper. Max flow rate is 65 GPM @ 80 PSI. I need to be able to enter a volume (e.g. 530 gallons) and have the arduino open the valve, count ticks from sensor, and shut off flow when the entered volume has been reached. I can handle real-time display, etc, etc. Plan on using Yun to allow web-based control & monitoring.
A couple of head-scratchers into which I've run:
- 1 1/4" flow meter. I can't seem to locate one that's under $900
- Valve type. Typically this process takes under 15 minutes. Somewhat concrned about powering a solenoid for that long. I've no experience implementing and h-bridge in arduino that woudl be required for a latching solenoid
I have a reasonable budget for this project, just can't seem to find the correct pieces and parts.
I can allay your fears about the solenoid valve operation. I have several 2" solenoid valves in my irrigation system that operate for many hours per day. Any heat produced is drawn away by the water. In addition, most valves of the size you need are "piloted valves". Meaning the solenoid only operates a tiny pin to open a port that allows the pressure side of the valve to fully open the actual valve. On closing the tiny port, the pressure differential now closes the larger valve.
My solenoid valves open to fill the 1,000 gallon tank from the domestic well. Another opens the tank to pump line so the irrigation water can flow to the sprinklers.
Paul
MorganS:
The city water authorities get very nervous when you attach something to their pipes. They require licensed plumbers for certain types of jobs.
Fortunately in our jurisdiction that is not the case. The facility has a 3" meter and backflow preventer. Our section of the building which is fed by 1 1/2" also has a BF preventer. GPI (gpimeters.net) has the meter I need for about $900 so you're spot on in that regard. Just the price of doing business.
Paul_KD7HB:
I can allay your fears about the solenoid valve operation. I have several 2" solenoid valves in my irrigation system that operate for many hours per day. Any heat produced is drawn away by the water.
Very good to know. Thanks!
wvmarle:
For your valve: maybe use a motorised normal valve, not a solenoid.
Yup. Good call. I've been looking at Belimo motorized valves that close in about 9 seconds.
I hope your fire suppression system, water sprinklers, is not part of the pipe you are turning off.
Paul
ebstauffer:
- 1 1/4" flow meter. I can't seem to locate one that's under $900
- Valve type. Typically this process takes under 15 minutes. Somewhat concrned about powering a solenoid for that long. I've no experience implementing and h-bridge in arduino that woudl be required for a latching solenoid
just can't seem to find the correct pieces and parts.
You clearly haven't been looking hard enough. $20 or so - each - should see you with both those devices. You can get complete kits with controller and display for under $100. No Arduino needed.
Your supply authority really shouldn't be interested on what you do on your side of their meter. Your insurance company might be though.
Paul_KD7HB:
I hope your fire suppression system, water sprinklers, is not part of the pipe you are turning off.
Paul
Per code, fire suppression is always on a separate service and always in black pipe with groove fittings, not copper.
Nick_Pyner:
You clearly haven't been looking hard enough. $20 or so - each - should see you with both those devices. You can get complete kits with controller and display for under $100. No Arduino needed.
Your supply authority really shouldn't be interested on what you do on your side of their meter. Your insurance company might be though.
I'd be really interested in a 1¼" flow meter for $20. I don't think they exist. The closest I've found is a 1½" meter from GPI which is $460.
Paul_KD7HB:
I hope your fire suppression system, water sprinklers, is not part of the pipe you are turning off.
Paul
I don't even know how to reply to something like this. It's not my first rodeo.
My water flow sensor (1/4" - larger ones cost a little more) cost me the equivalent of USD 3. Just found a 1 1/2" one that sells for the equivalent of just over USD 12. 1 1/4" appears to be a rather unusual size, but that can be fixed with a simple adapter.
Nick_Pyner:
ebay 301998597438
That's a beautiful thing. I've reached out to the sell to see what the max PSI & GPM it will handle. Many thanks!
wvmarle:
My water flow sensor (1/4" - larger ones cost a little more) cost me the equivalent of USD 3. Just found a 1 1/2" one that sells for the equivalent of just over USD 12. 1 1/4" appears to be a rather unusual size, but that can be fixed with a simple adapter.
It looks like the DN50, which I believe is near 2", is $90. A real bargain! Need to try to get specs on it for pulses per liter / gallon etc, and max GPM / PSI. Thanks for that.
ebstauffer:
It looks like the DN50, which I believe is near 2", is $90. A real bargain! Need to try to get specs on it for pulses per liter / gallon etc, and max GPM / PSI. Thanks for that.
Specs are a bit lower in the link that I posted - unfortunately all in images so you have to be able to read at least a little Chinese as Google Translate can't handle it (or point your phone with Google Translate at the image on the screen, their OCR combined with translation works remarkably well).
DN50 = 2" (2寸 in Chinese)
It's rated at 25 m3/hr, the smallest meter is 0.1 litres. It seems the smallest dial has a magnet attached to it producing one or two pulses per rotation, so that would be 1 or 2 pulses per litre. Hall effect sensor and reed switch versions are available.
I can't find pressure ratings - they're meant for domestic type supplies.
I should add: there may be sellers with better deals; this was just one of the very first ones that came up on a quick search. I never bought anything from this shop myself.
All these devices are good for 1.5 MPa which is a lot more than you are talking about. A DN50 should do 300 l/min, which is about what you want. They are bigger than I use, so $40.
wvmarle:
Specs are a bit lower in the link that I posted - unfortunately all in images so you have to be able to read at least a little Chinese as Google Translate can't handle it (or point your phone with Google Translate at the image on the screen, their OCR combined with translation works remarkably well).
DN50 = 2" (2寸 in Chinese)
It's rated at 25 m3/hr, the smallest meter is 0.1 litres. It seems the smallest dial has a magnet attached to it producing one or two pulses per rotation, so that would be 1 or 2 pulses per litre. Hall effect sensor and reed switch versions are available.
I can't find pressure ratings - they're meant for domestic type supplies.
I should add: there may be sellers with better deals; this was just one of the very first ones that came up on a quick search. I never bought anything from this shop myself.
Ive worked with a China-based contract programmer in the past, I believe I'll ask him to translate. Thanks.