I'm designing a sprinkler system for my yard. This will be a fairly complex
system, as the area to be watered is fairly large. I'm going to DIY install
the system. I have a good handle on most everything that needs to done,
however, I need help determining my available flow in GPM.

I checked pressure at an outside faucet, and have a static 62 PSI. I checked
flow at the same location and have 8 GPM. I was doubtful of the 8 GPM
reading, because that sillcock is supplied by a 1/2" pipe. So I opened up
the shower and bathtub, and ticked off 14 GPM by using a timer and watching
the gallons go by on my watermeter in the basement.

So, which reading is correct? Is there a better, more accurate way to
determine GPM? I really want to get this right. I have a 1" watermeter,
which has a full 1" ID poly supply pipe. The supply pipe is 50 ft. long,
from the street to my house.

Second question:
The spot where I plan to tap for the system is about 4ft after the
watermeter. The pipe is 3/4" copper. To maximize flow, should I replace the
3/4" with 1"? Or will such a short length of pipe matter? I plan to use 1
1/4" PVC going to the zone valves as well. Is this OK?

Thanks for any advice!

J.A. Michel

"J.A. Michel" wrote in message
...
I'm designing a sprinkler system for my yard. This will be a fairly
complex system, as the area to be watered is fairly large. I'm going to
DIY install the system. I have a good handle on most everything that needs
to done, however, I need help determining my available flow in GPM.

Neither of your measurments is accurate because of restrictions in the
valves. You need to measure the flow at the open end of the pipe.

According to my Pocket Ref, a 1" nozzle at 60 psi can have a flow rate of
232 gpm. There will be friction losses too. A 1/4" nozzle would have the
14 gpm that you measured. Considering the opening at the valve stem, that
may be correct. Even your water meter will have some restrictions in it, as
does your main valve.




Second question:
The spot where I plan to tap for the system is about 4ft after the
watermeter. The pipe is 3/4" copper. To maximize flow, should I replace
the 3/4" with 1"? Or will such a short length of pipe matter? I plan to
use 1 1/4" PVC going to the zone valves as well. Is this OK?

The flow will be restricted by the smallest pipe diameter on the water's
path. The 1 1/4" going to the zone vales will not improve anything.
Changing the 3/4" line will only help if the meter is not restricted down to
that size.

There are other ways to assure the flow you need. Since you have zone
valves, set the timer to do different zones at different times. Not every
portion of your lawn needs the same amount of water anyway. An please,
don't be like some of the idiots that have the sprinklers on in the rain.

Smarter would be to plant a yard that does not need added water to thrive.
As water becomes more difficult to supply, large yards with perfectly
manicured lawns will be looked on by society in the same category as smokers
and Hummer drivers.

"Edwin Pawlowski" wrote in message
om...

"J.A. Michel" wrote in message
...
I'm designing a sprinkler system for my yard. This will be a fairly
complex system, as the area to be watered is fairly large. I'm going to
DIY install the system. I have a good handle on most everything that
needs to done, however, I need help determining my available flow in GPM.

Neither of your measurments is accurate because of restrictions in the
valves. You need to measure the flow at the open end of the pipe.

According to my Pocket Ref, a 1" nozzle at 60 psi can have a flow rate of
232 gpm. There will be friction losses too.

That would give you a velocity of almost 90 feet per second providing you
can overcome a 3000 ft. of head (1500 psig) friction loss!

Try turning the pocket reference upside down and read it WITH your
glasses on this time. ;-)


-zero

"J.A. Michel" wrote in message
...
I'm designing a sprinkler system for my yard. This will be a fairly
complex system, as the area to be watered is fairly large. I'm going to
DIY install the system.

I have a good handle on most everything that needs to done,
however, I need help determining my available flow in GPM.

This should cover just about everything
http://www.irrigationtutorials.com/sprinkler00.htm


-zero

"J.A. Michel" wrote in message
...
I'm designing a sprinkler system for my yard. This will be a fairly
complex system, as the area to be watered is fairly large. I'm going to
DIY install the system. I have a good handle on most everything that needs
to done, however, I need help determining my available flow in GPM.

I checked pressure at an outside faucet, and have a static 62 PSI. I
checked flow at the same location and have 8 GPM. I was doubtful of the 8
GPM reading, because that sillcock is supplied by a 1/2" pipe. So I opened
up the shower and bathtub, and ticked off 14 GPM by using a timer and
watching the gallons go by on my watermeter in the basement.

So, which reading is correct? Is there a better, more accurate way to
determine GPM? I really want to get this right. I have a 1" watermeter,
which has a full 1" ID poly supply pipe. The supply pipe is 50 ft. long,
from the street to my house.

Second question:
The spot where I plan to tap for the system is about 4ft after the
watermeter. The pipe is 3/4" copper. To maximize flow, should I replace
the 3/4" with 1"? Or will such a short length of pipe matter? I plan to
use 1 1/4" PVC going to the zone valves as well. Is this OK?

Thanks for any advice!

J.A. Michel

Your water pressure, 62 psi is a needed figure. With no flow, it is the
same as the pressure in your water main. The flow at a tap is not a useful
figure.

Given that you are tapping your incoming service near the meter, your
procedure will be something like this --

1. Lay out a pattern for one area assuming a pressure of about 20 psi
(possibly more) at the sprinkler heads. Total the delivery in gpm (gallons
per minute) for all the heads on the branch. Then determine the pressure
drop between the water main and the sprinkler heads (more later). If that
drop is more than 62 minus the pressure at the sprinkler heads (possibly
62 - 20 = 42 psi) you must reduce the number of heads on the branch. If it
is less you may be able to add more heads, but its best to have some reserve
pressure in the system. You can always reduce the pressure at the sprinkler
valve.

The pressure drop between the main and the sprinkler heads depends on the
flow rate in gpm and the pressure losses in the water meter, piping and
valves in the line. You get appropriate information from the people who
sell you the hardware. Generally, valve and sprinkler manufacturers provide
good data sheets to use with their products. I think that the drop in
pressure in the meter at a large flow can be about 7 psi. Drop through
sprinkler valves is about the same. The pressure drop in pipe depends on
the type, diameter and length. Generally, 3/4 inch pipe is used. Long runs
may require larger pipe or a lesser number of sprinkler heads.

Pressure drops in meter, valves and pipe increase dramatically as more flow
is demanded. It's a square law relationship so if you were to increase the
flow 40%, the pressure drop would double.

By sure to get the sprinkler manufacturers data sheet. The information it
provides is essential.

SJF

"zero" wrote in message

That would give you a velocity of almost 90 feet per second providing
you can overcome a 3000 ft. of head (1500 psig) friction loss!

Try turning the pocket reference upside down and read it WITH your
glasses on this time. ;-)


That is what it says on page 420. What is his gpm then?

"Edwin Pawlowski" wrote in message
m...

"zero" wrote in message

That would give you a velocity of almost 90 feet per second providing
you can overcome a 3000 ft. of head (1500 psig) friction loss!

Try turning the pocket reference upside down and read it WITH your
glasses on this time. ;-)


That is what it says on page 420.

Rip 419-421 out then. ;-)

What is his gpm then?

I don't know. There's not enough info to tell.
With the known Cv of the meter you could at least tell a little more,,, but
it sounds like
he's thinking to spray the whole yard at one time!

-zero

J.A. Michel wrote:
I'm designing a sprinkler system for my yard. This will be a fairly complex
system, as the area to be watered is fairly large. I'm going to DIY install
the system. I have a good handle on most everything that needs to done,
however, I need help determining my available flow in GPM.

I checked pressure at an outside faucet, and have a static 62 PSI. I checked
flow at the same location and have 8 GPM. I was doubtful of the 8 GPM
reading, because that sillcock is supplied by a 1/2" pipe. So I opened up
the shower and bathtub, and ticked off 14 GPM by using a timer and watching
the gallons go by on my watermeter in the basement.

So, which reading is correct? Is there a better, more accurate way to
determine GPM? I really want to get this right. I have a 1" watermeter,
which has a full 1" ID poly supply pipe. The supply pipe is 50 ft. long,
from the street to my house.

Second question:
The spot where I plan to tap for the system is about 4ft after the
watermeter. The pipe is 3/4" copper. To maximize flow, should I replace the
3/4" with 1"? Or will such a short length of pipe matter? I plan to use 1
1/4" PVC going to the zone valves as well. Is this OK?

http://www.irrigationtutorials.com/sprinkler00.htm Very complete
workup.

R

J.A. Michel wrote:
I'm designing a sprinkler system for my yard. This will be a fairly complex
system, as the area to be watered is fairly large. I'm going to DIY install
the system. I have a good handle on most everything that needs to done,
however, I need help determining my available flow in GPM.

I checked pressure at an outside faucet, and have a static 62 PSI. I checked
flow at the same location and have 8 GPM. I was doubtful of the 8 GPM
reading, because that sillcock is supplied by a 1/2" pipe. So I opened up
the shower and bathtub, and ticked off 14 GPM by using a timer and watching
the gallons go by on my watermeter in the basement.

So, which reading is correct? Is there a better, more accurate way to
determine GPM? I really want to get this right. I have a 1" watermeter,
which has a full 1" ID poly supply pipe. The supply pipe is 50 ft. long,
from the street to my house.

Second question:
The spot where I plan to tap for the system is about 4ft after the
watermeter. The pipe is 3/4" copper. To maximize flow, should I replace the
3/4" with 1"? Or will such a short length of pipe matter? I plan to use 1
1/4" PVC going to the zone valves as well. Is this OK?

Thanks for any advice!

J.A. Michel


http://www.irrigationtutorials.com/sprinkler00.htm

What additional information would be helpful? I'm planning on holding my
zones to 10 GPM. Just trying to make sure I would have 10 GPM available so
that each zone would operate properly.

J.A. Michel

"zero" wrote in message
. ..

"Edwin Pawlowski" wrote in message
m...

"zero" wrote in message

That would give you a velocity of almost 90 feet per second providing
you can overcome a 3000 ft. of head (1500 psig) friction loss!

Try turning the pocket reference upside down and read it WITH your
glasses on this time. ;-)


That is what it says on page 420.

Rip 419-421 out then. ;-)

What is his gpm then?

I don't know. There's not enough info to tell.
With the known Cv of the meter you could at least tell a little more,,,
but it sounds like
he's thinking to spray the whole yard at one time!

-zero

"Edwin Pawlowski" wrote in message
om...

"J.A. Michel" wrote in message
...
I'm designing a sprinkler system for my yard. This will be a fairly
complex system, as the area to be watered is fairly large. I'm going to
DIY install the system. I have a good handle on most everything that
needs to done, however, I need help determining my available flow in GPM.

Neither of your measurments is accurate because of restrictions in the
valves. You need to measure the flow at the open end of the pipe.

According to my Pocket Ref, a 1" nozzle at 60 psi can have a flow rate of
232 gpm. There will be friction losses too. A 1/4" nozzle would have the
14 gpm that you measured. Considering the opening at the valve stem, that
may be correct. Even your water meter will have some restrictions in it,
as does your main valve.

232 GPM? Maybe from a fire hydrant, but not a house. Perhaps it's 23.2?





Second question:
The spot where I plan to tap for the system is about 4ft after the
watermeter. The pipe is 3/4" copper. To maximize flow, should I replace
the 3/4" with 1"? Or will such a short length of pipe matter? I plan to
use 1 1/4" PVC going to the zone valves as well. Is this OK?

The flow will be restricted by the smallest pipe diameter on the water's
path. The 1 1/4" going to the zone vales will not improve anything.
Changing the 3/4" line will only help if the meter is not restricted down
to that size.

Agreed. The short section of 3/4" will be replaced with 1" copper, and main
to the zones will be 1"pipe.


There are other ways to assure the flow you need. Since you have zone
valves, set the timer to do different zones at different times. Not every
portion of your lawn needs the same amount of water anyway. An please,
don't be like some of the idiots that have the sprinklers on in the rain.

Agreed. I'll try not to.


Smarter would be to plant a yard that does not need added water to
thrive.


I have no yard right now. Anything I plant will require water.


As water becomes more difficult to supply, large yards with perfectly
manicured lawns will be looked on by society in the same category as
smokers and Hummer drivers.

Spare me the tree hugger bull****!!

I want a really nice green perfectly manicured yard, and I don't rightly
give a **** what the tree-huggers say.
That's why I'm putting the system in.duh I also am a smoker, if that
makes a difference. My employer
has a major contract to machine parts for a fire supression systems that are
installed aboard HumVees. Those
Hummers are wonderful vehicles, which are bringing home our men and women in
uniform who would have
otherwise come home in a body bag. If someone wants to drive a humvee on
the street, that's fine with me! It's their money
after all. The tree huggers that whine about hummers are just jealous that
they can't afford one.

"J.A. Michel" wrote in message

232 GPM? Maybe from a fire hydrant, but not a house. Perhaps it's 23.2?


No, 232. As for a hydrant:

http://www.firehydrant.org/info/faqs_ask7.html
Our hydrants are pressurized (in general) at about 60 PSI (and flow at about
750 GPM at that pressure), and have varying flow capacities. In pumping to a
remote fire we want to maximize water flow to the site, and we have a few
options:

First, we can hook up the hydrant to the pumper at the 4.5" discharge with
an adapter and a 6" cloth hose (soft suction). The pumper has upper limits
of 1500 GPM and 150 PSI, and the 4" hose line we are feeding from the pumper
has a pressure rating of 180 PSI.