I bought some water meters from watermeters.com a while back, the largest they had with the pulse wire was 3/4". My irrigation company installed 1" PVC pipe coming from the house. Would it be too much of a bottleneck to use the 3/4" meter on this? I think the most water used per minute is about 6 gallons. Thanks in advance.
Water Meter 3/4" on 1" pipe?
- Thread starter standon
- Start date
pete_c
Guru
My water comes in at 1" and is actually reduced at the water utilities meter to 3/4". From here it goes back to 1" then to my supplimental pump (1") reduced back down to 3/4" at the purchased water meter; then back up to 1" (all copper). I don't really notice the bottle necks. I have a water pressure meter which typically always shows around 35-40. All of supply is copper. I am not a plumber; but would have to assume that this methodology is kind of kludgy.
programmergeek
Active Member
Not a problem most meters are 1/2" or 3/4". Don't ask me why but it doesn't create a bottle neck. It is actually more about what type of water pressure you have in your area.
Only one molecule of water can occupy the same space at the same time. So when the diameter gets smaller the water goes faster through that section of pipe(or in this case the meter. Simply stated. when the line gets smaller the rate of water gets faster to compensate.
There is a recommended max flow rate through a regular 3/4" or 1/2" line. Well as you over a certain GPM flow rate you will hear it in the pipes and if you get really fast you can actually wear down the thin pipe. But a meter is normally in the basement and is thick walled so downsizing it one size is not an issue with either wear or noise. Water will work just fine.
There is a recommended max flow rate through a regular 3/4" or 1/2" line. Well as you over a certain GPM flow rate you will hear it in the pipes and if you get really fast you can actually wear down the thin pipe. But a meter is normally in the basement and is thick walled so downsizing it one size is not an issue with either wear or noise. Water will work just fine.
apostolakisl
Senior Member
You need to determine your overall need for flow rate and then look at what the system can provide. Reistance to flow is complicated but diamter and length are the main drivers. Smaller diameter increases resistance exponentially. Increased length raises resistance linearly. If you lose diamter for a very short section of pipe, it won't damage overall resistance very much. When you have a long run, you need more diameter.
Anyway, since a valve bottleneck is only a few inches long, you can get away with it in typical situations like this.
Anyway, since a valve bottleneck is only a few inches long, you can get away with it in typical situations like this.
Thanks for all the help. I'm going to give it a try tomorrow and I'll post back. I feel like it should be fine. I found this link and looks like 3/4" should handle 11GPM. I think the sprinklers use 1.6-1.8GPM each, 3 run at a time. Even over estimating at 2.5GPM it shouldn't have a problem with the demand... as I see it.
Thanks again.
Thanks again.
znelbok
Active Member
It will create a small botleneck, but becasue the length is short (insignificant almost) the pressure loss is negligble. Longs runs should be large diameter.
In industry, we often have to put in smaller diatemer flow meters to get the flow velocity up to a readable level, but becuase hte length is short, the pressure loss is not a problem.
So haveing a small flow meter may actually be better for you as you may get more consistent results.
Mick
In industry, we often have to put in smaller diatemer flow meters to get the flow velocity up to a readable level, but becuase hte length is short, the pressure loss is not a problem.
So haveing a small flow meter may actually be better for you as you may get more consistent results.
Mick
I hooked everything up today, looks to be fine. About 6gpm on the dial. Noise is pretty non-existant, only when irrigation valves initially open does it make any noise. Thanks for all the help!
As long as I'm asking stupid questions... How do I hook the pulse up to the Elk M1? Do I run the wires to a DC power distributor and break into the positive wire to the Elk? At roughly 1 gallon per second, is the pulse too fast for Elk to keep track of?
felixrosbergen
Senior Member
+1. This should be no issue. I have the same 3/4" meter on a 1" copper mainlines.
Just look at the pressure loss charts for it. At around 6 GPM the pressure loss is absolutely minimal. If you were doing 20 GPM or something you may want to reconsider. But at 6 or 8 GPM it's not an issue.
I had contemplated getting the 1" meter as well. They do make a 1" with pulse output as well, but it's nearly double the price of the 3/4".
The noise you hear when you turn a zone on is the initial inrush when the meter goes much faster than later...i would think you would hear the same on a 1" meter.
Just look at the pressure loss charts for it. At around 6 GPM the pressure loss is absolutely minimal. If you were doing 20 GPM or something you may want to reconsider. But at 6 or 8 GPM it's not an issue.
I had contemplated getting the 1" meter as well. They do make a 1" with pulse output as well, but it's nearly double the price of the 3/4".
The noise you hear when you turn a zone on is the initial inrush when the meter goes much faster than later...i would think you would hear the same on a 1" meter.
felixrosbergen
Senior Member
Just noticed the 2nd part of the question.
Just set a zone on the ELK to the 'Non Alarm type' ..i can't remember if it's normally open or closed.
The pulse speed is not very high and the ELK will see it. You can consider turning on 'fast loop response' or whatever that setting is for the zone (i think this can only be done on the Main unit and not on the extenders, but i could be wrong).
Anyway...the pulse counter just acts the same as any door/window switch. Put one less on the 'NEG' and the other on the zone input.
I did this about 6 weeks ago and the ELK is still 100% in line with the meter itself after 68.000 pulses.
I thought i was going to have to get a 1-wire pulse counters, etc...but this turned out much easier than expected.
Sorry i'm a bit sketchy on the details and settings, let me know if you have issue and i'll look up the exact settings and such.
Just set a zone on the ELK to the 'Non Alarm type' ..i can't remember if it's normally open or closed.
The pulse speed is not very high and the ELK will see it. You can consider turning on 'fast loop response' or whatever that setting is for the zone (i think this can only be done on the Main unit and not on the extenders, but i could be wrong).
Anyway...the pulse counter just acts the same as any door/window switch. Put one less on the 'NEG' and the other on the zone input.
I did this about 6 weeks ago and the ELK is still 100% in line with the meter itself after 68.000 pulses.
I thought i was going to have to get a 1-wire pulse counters, etc...but this turned out much easier than expected.
Sorry i'm a bit sketchy on the details and settings, let me know if you have issue and i'll look up the exact settings and such.
So no power source needed? Is there a battery inside the meter or something? I for some reason thought it was a magnetic reed switch inside and that they always needed some power. I'm a dummy about these things though. Thanks!
felixrosbergen
Senior Member
Assuming you got the DLJ 75C http://shop.watermeters.com/product.sc;jse...mp;categoryId=1
The switchs/pulse functions just the same as a door/window switch. The ELK will provide a circuit 'though it' and it acts as if closing and opening that switch and the ELK can count that.
So just the 2 wires should work fine.
drozwood90
Senior Member
Pete,
That's crazy!
Sounds like the plumber was running out of parts and had to finish it "under-the-gun".
Just surprises me, sounds like something you would have said something about (I know I would have...had I noticed it).
--Dan
Photon
Active Member
The municipality that provides our water charges a quarterly fee based on the size of the meter and adds $1.60 per 1000 gallons used. Had I known this, and had I had the plumber throttle down to a 3/4" meter, I would save about $40/year on the base rate. It could be worse; had he installed a 1 1/4" meter, it would add $80/year to the base rate.
programmergeek
Active Member
Most of the sprinkler systems we have installed run through a 1/2 meter no problem. Again water pressure is your friend in a sprinkler system it is more if a affect than the diamater of the meter. Also tap the sprinkler system before the pressure reg if you can/
Similar threads
