Getting a new water meter...can I have them....

There is 5/8" tubing, and fittings to match, but 1/2" tubing would have a 5/8" OD, and I have seen them as service lines. And of course, the flow is miserable, no matter how high the pressure, so a sprinkler system would have to be laid out in small sections.

If all the interest in water meters comes from a recent purchase of a lawn sprinkler system, then rework the sprinkler system.

Five-eights inch water meters and 3/4 inch (copper) supply lines are common. I don't think I have ever seen or heard of a single-family residence having anything larger than a 3/4 inch meter although the piping may be as large as one inch. In many (most?) areas a one-inch water meter would also have a surcharge added to the water billing.

My own meter is a 3/4 inch and while I do not know the size from the city main to the meter the line from the meter to my house is one inch.

Another factor may be elevation. Is your house at a significant height above the street? My meter is near the street but my house is fifteen to twenty feet above street level. For every foot of elevation you will lose almost one-half PSI pressure.

OK, lets see......yes there is a back flow valve on the lawn sprinkler system. I may have been wrong on the 5/8" line so I will check that tonight. I am going to buy a pressure gauge on the way home tonight so I can get a reading off my system and the neighbors. I've allready placed a call to the sprinkler system guy and it's been in place for at least 10 years. Seemed to work fine until this past year. I'm guessing one fix is to reduce the number of heads per zone, but that would require adding more zones and $$$.

The pressure and flow in the house is OK, not great, but tolorable. Biggest beaf is the sprinkler system and the hose bib that I use for washing cars, ect. I know the problem with the hose bib is that it has about 30' of 3/4" copper reduced down to about 30' of 1/2" copper and then a 100' 5/8" garden hose. Yea, that is a long way for much to get through. I told the plumber to use 3/4" on that last 30' but he did not and the concrete was down before I noticed.

Back later with more data...................

There are certain backflow failures that restrict flow to a sprinkler system. Sprinkler zone valves can do the same, but you'd see a difference between zones.

There are also problems on the municipal side that can reduce supply pressure, and you may never get a good explanation for temporary periods of lower pressure. (water departments don't like to admit they've screwed up)

OK, here's a bunch of data to mull over.......Presuure at the closest bib to the supply is 50 psi. If I turn on the kitchen faucet, which is about 10 ft from the source, it drops to 45 psi. When I turn on the sprinkler system, pressure drops to 30 psi at the lowest with zone 4 on, and 32 psi for the other 7 zones. Zone 4 is the one that is causing the most problems and the range for each head is about 18 ft. Oh, and there are 5 heads in this zone.

Other zones with the same style heads have ranges from 21' to 24'. Some have 4 heads, one even has 6 and still gets 24' distance. Zone 3 has 4 rotary heads and two spray heads and the range is 21' for two and 18' for the other two. (I assume that the two going 18' need to be cleaned out.)

Checked the neighbors hose bib closest to his meter and it's 48 psi, so I guess I'm getting as much as everyone else in the area.

So.............based on this I'm guessing that I either have a bunch of spray heads that need to be cleaned or that there is possibly a faulty valve? What else do I nee to check? The supply line from the street is copper and has an outside dia of .901' which would indicate 3/4".

I guess that I should post this over in the lawn system forum, but if any of you can share some insight, I would appreciate it.

SteveL1 said:

OK, here's a bunch of data to mull over.......Presuure at the closest bib to the supply is 50 psi. If I turn on the kitchen faucet, which is about 10 ft from the source, it drops to 45 psi. When I turn on the sprinkler system, pressure drops to 30 psi at the lowest with zone 4 on, and 32 psi for the other 7 zones. Zone 4 is the one that is causing the most problems and the range for each head is about 18 ft. Oh, and there are 5 heads in this zone.

I guess that I should post this over in the lawn system forum, but if any of you can share some insight, I would appreciate it.

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You need to match every one of those pressure measurements with flow (Gallons per minute) to make any sense out of them.

You don't need a bucket; you have that nice new digital water meter. Get a watch with sweep second hand, or some other device, and use it to measure flow rate for each condition.

If those pressure readings are a result of 15 GPM of flow, then you need to cut down the demand.

If the low pressure readings are a result of 3 GPM of flow then you have a problem with restrictions in the pipe.

Are all of those pressure measurements at the hose bib?

You should also try to get pressure measurements near the place where the water is being used. It will be much lower at that point. A range of 18 ft is pretty small for an irrigation system.

You might improve the situation by putting lower flow nozzles at each location in the irrigation system. If you cut the flow by 1/3 you will reduce the pressure drop caused by that system by about 1/2.

GrumpyPlumber said:

Also, regardless where you put the guage, you'll get the same psi reading unless you're putting the guage at a higher or lower elevation (pressure decreases by .434 psi per foot of height).

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That is not quite true.

The pressure losses vary with the length and size of pipe from source to discharge. If there is no flow the pressure is the same everywhere except for small differences due to elevation, but if there is flow the pressure at different places can be quite different.

The gauge on the hose bib near where the water comes into the house will measure the pressure loss in the inlet pipe from the street main.

Using the example that the owner has given with the irrigation system, if the pressure at the hose bib is 20 psi below the static (no flow) pressure, then the pressure at the end of the irrigation line near the nozzle may be 30 psi below the static pressure.

Pressure measurements are required at both places to fully understand and be able to fix the problem.

OK, here's some more data......filling a 5 gal bucket in the upstairs bath tub took 67 seconds. The same bucket in the kitchen sink, 2 min. 35 sec. A hose bib in the garage roughly 30' from the meter.....35 sec. !!!! Yikes, 35 seconds. And I made a huge mess trying to hold the bucket up while I was looking at my watch!

Now the meter readings....With zone #4, which is the worst for coverage, I got 1.25 cu ft per minute. Zone 3, which is about the same for coverage, 1.25 cu ft/m. Zone 6, which has heads shooting at least 24'+.....1.2 cu ft/m.

And just for giggles, the bath tub that filled the bucket in 67 sec showed .55 cu ft/m.

So, what have I learned? First is that I should have paid a lot more attention in my fluid dynamics classes 30 years ago and that it seems that I have a lot more pressure/flow at 9:00 PM than I do in the day time when all of the repair guys show up.

So what does all this mean to you guys?

You are able to get 9 GPM through the system. That is not great but not too bad for a residential system.

The difference between 9 GPM in the sprinkles and 4.5 GPM at the bathtub is related to pipe and valve losses.

It is hard to reach a conclusion until you provide a correlation of flows and pressure measurements.

What is the static pressure near the inlet before you start the test, what is the pressure near the inlet when you have the flows that you are reporting, and what is the pressure near the point of use when the sprinklers are reaching 18 ft and when they are reaching 24 ft?