this is how I got 28 gpm from a 3/4"

[turfman59]

We dug up a 3/4 inch galv line 8 ft away from a 10 inch concrete main, put in a T a gate valve a blow out after that.

Back hoe charge for the digging 75.00 misc fittings, shut off $110.00 charge from the plumber 90.00 well under the citys charge for tapping the main of 650.00


did a flow test right around 28 gpm

hooked up 6 rb 5000's ss with 3 gpm and got 35 feet of throw..

after I hook up the bfp and the meter I should be able to flow at least 20 gpm at around 45 psi

any thoughts ?????????

[DanaMac]

Had you already installed the pressure regulator to get the 45 psi? Or is that to follow when you do the bfp? Is that something the city would have installed with their price? Was the $75 for the backhoe with labor included? Is it all backfilled yet? Or more labor to bury it?

Just asking ????

Also why do you want to do it that way? I hate having to raplace the gate valve 6' in the freaking ground when it decides to not shut down completely and seep past to the bfp in the winter.

[turfman59]

Originally posted by DanaMac
Had you already installed the pressure regulator to get the 45 psi? Or is that to follow when you do the bfp? Is that something the city would have installed with their price? Was the $75 for the backhoe with labor included? Is it all backfilled yet? Or more labor to bury it?

Just asking ????

Also why do you want to do it that way? I hate having to raplace the gate valve 6' in the freaking ground when it decides to not shut down completely and seep past to the bfp in the winter. yes thats the labor included on the backhoe.

the 45 psi will be theprojected dynamic pressure with the 6 heads

the reson I did it was to shorten the irrigation time its a big lawn with a 3/4 inch galvenized service thats 75 feet long I never would have been able to do it. I would have been lucky to get 8 -9 gpm

[brentlent]

I would use a 3/4" meter (min.) when planning on 20 GPM
Also,
20 GPM = 6.5 PSI loss thru meter. You can push a meter past it's max flow, but it will wear out and have an even greater PSI loss. I've worked on a couple systems that you can hear the meter spinning over the sound of the rotors.

What size main line are you planning on running and how many feet?


brent

[jman00]

still using 3gpm for each head. Also what is the pressure loss of 20gpm though 3/4 i dont have my book also what is the pressure loss through the meter and back flow you might not have enough pressure to run those heads. Are you going to continue your 3/4 for the main line and the laterals or make it the right size pipe for that gallonage.

Also i am confused as to what you are doing. I read your post and are you hooking up to the city water with out tellin them. I didnt know a plumber could tap into city water. If you are not doing that then why are you using a meter if you are going in after the water meter then another meter is not needed. Either way i thought you needed a city employee to at least look at the work and get it inspected.

[brentlent]

I would suggest 1.5" main. If you tried to get by with 3/4" your water velocity would be 9.4 ft/sec and you would have major water hammer and problems. Also, you would loose 15 psi for every 100 ft. of main.

Most cities say the water line up to the meter is their property and yours after it. How did you Tee off the service (before the meter) without getting all wet?

[turfman59]

This is how
had the city shut the water off
8 ft away from that, put a T in and a 1 1/4 main to the bfp and then the meter ( seperate ) from the house.

using a badger meter thats capacity is 25 gpm

all full circle heads will be 4 gpm and seperate from 1/2 turns and 1/4 turns.. full circles are space to fill in behind 1/4 trns and 1/2 turns......

The friction loss wont be much more than 6 psi from the 3/4 inch galvanized being its only 8 ft

[SprinklerGuy]

Wait a sec....you cut into the 3/4 line and put in a 1.25 inch mainline? And you cut a "t" fitting into this 3/4 galvanized? Then upsized the outlet of the "t" fitting to accomodate a 1.25 " mainline? Am I hearing this right???????


Did you use a galvanized t or brass t?
Ever hear of electrolysis?

Good luck, glad it's not my house if the above scenario is correct.

[turfman59]

The city gave me a Brass and copper fitting all compression.

I have heard of electrolysis, Would like to expand further or just leave on an inuendo???

[SprinklerGuy]

nope...if you understand it then no need to elaborate.

Did you though feed the 1.25 inch main with 3/4 inch galvanized?

[turfman59]

yes

[SprinklerGuy]

I would think that if you exceed about 10-12 gpm on a zone, you will have water hammer.....see it all the time. Usually the galvanized is corroded inside pretty badly....may or may not be. If you are trying to run more than that, your 1.25 inch mainline will never stay full.........lots of velocity........valve shuts off.....bam! I could be wrong...have been before.

Good luck to you.

[greenworldh20]

turfman,

i agree with tony...i do not understand why you tapped into a 3/4" line and teed off with a bigger line...but hey, if ya got paid...what more do ya want?


brian...

also, i am glad that it is not my house either....

no harm intended, turfman.

[turfman59]

This is why
1. very sandy soil and a large lot

2. service coming to the house is 80 ft long and 35 year old gavinized 3/4'" pipe

3. 8 gallons per minute would not be acceptable for the available window to water

4. I have 8 gallons per minute at my house and sandy soil also and it suffers during drought. I live 3 blocks away and during drought the sprinkler has to run during the day to keep up, Which waste's water and resources.

5. I would rather spend time hooking up to the city service than adding 5 more valves and 15 more heads,

6. no one has said why this is an inadequate or unreputable way of constructing a system.

My point is this,
if you are not in the business of constructive or instructive dialogue BUTT OUT. If you want to sit at home and shake your head thats fine, but dont wave your finger at me without telling me what I have done wrong.

Thanks again for your attention to this detail

[turfman59]

I still dont feel better after that rant.......

thanks tony for the response. I do plan to run around 18 gpm on one zone only... If I nozzle down I will reduce it to 15 gpm. I cut back initially on the design so I will not have a problem with distance on the radius, and should have close to 75% distribution efficiency in the system either way. I ran this by you guys earlier last week on a similiar post and nobody even flinched on this idea

Thanks again for you time

[HBFOXJr]

1. 28gpm is open flow, not at a useable psi

2. I don't like galvanized because of corrosion and growing shut

3. If the brass is isolated via rubber gaskets from the galvanized, no problem

4. He upsized the main because he wanted to keep the friction loss in the main to a minimum, any thing over 15 gpm would start dogging it if you had much 1" main

5. Bruce why you doing separate zones for the FC heads if your gonna use matched prcip nozzles? If your not doing matched precip why not? 4+ gpm fulls and 2+ gpm 1/2's at 30-33 feet on center will give a precip of approx .4"/Hr

6. Water hammer? The city and the house wil never feel it out that far and the effect will be minimal because stuff gets big so close.

7. My book says 3/4" sch 40 galvanized steel pipe looses 25 psi/100 ft. That translates to a 2psi loss in 8 ft for new clean pipe.

8. Gate valves are unreliable. Replace that witha brass ball valve or a brass angle valve as appropriate.

What else?

[turfman59]

Originally posted by HBFOXJr
[B

2.
6. Water hammer? The city and the house wil never feel it out that far and the effect will be minimal because stuff gets big so close.


What else? [/B] what does the last 5 or so words mean?

[HBFOXJr]

Big main is gonna get minor shock. Heaviest hit will be be where the 3/4 galv goes into the big main fitting. But that sucker won't feel too much.

[SprinklerGuy]

MAYBE I am confused...

Here is what I am confused about


We dug up a 3/4 inch galv line 8 ft away from a 10 inch concrete main, put in a T a gate valve a blow out after that.

My concern is that you are feeding your 1.25 inch mainline...with an old 3/4 inch galvanized pipe that you put a "t" into! Is that correct or not? Am I reading it right or am I not? Did you cut into a 3/4 inch galvanized pipe and put a "t" fitting into it? Did you then upsize from that 3/4 inch "t" into your NEW 1.25 inch backflow preventer? If so, my thoughts still stand....why would you supply a 1.25 inch sprinkler mainline with an old 3/4 inch galvanized pipe? If I am wrong about what I think you are doing...I am sorry, if you are indeed supplying a 1.25 inch mainline with old 3/4 inch galvanized...I still think that is the wrong thing to do.....my opinion. I wouldn't run jack off of a 3/4 inch galvanized mainline...I don't care if it was 8 feet away from a 20" inch concrete pipe or a 10" concrete pipe......you still are trying to fill a 1.25 inch pipe from 8 feet of 3/4 inch galvanized...


I'm sorry if I am wrong about what you are doing...perhaps I can't read, but if that is what you are doing, I think it is a bad idea.

[turfman59]

I am sorry for confusing everyone

I used a Ball valve with rubber compression fittings, my terminology is a bit under developed.

Tony why is it Bad,,,, I dont understand your concern for this modifacation....and what in your opinion would have been a better resolution???

[Ground Master]

Bruce your system design will work fine at even 18 gpm. The only potential problem will be the corrison of the 3/4" galvy line over time. If your able to move closer to the city main, you may want to consider that. Perhaps you could take some pictures as you do this job?

Sprinkler guy- the 1-1/4" line will have no problem "filling" from the 8 feet of 3/4" line.

[turfman59]

Oh by the way I used approximately 6 ft of 1 inch copper after the ball valve and blow out attachment until I could tie into it with the plastic that is 1 1/4 inches main line.

Man this post has got a lot of readers..............

[SprinklerGuy]

Your system is limited to the 3/4 inch galvanized pipes capacity....I wouldn't say it would be more than 12 - 15 gallons per minute....maybe it is more...BUT....I don't think it will keep the 1.25 inch mainline full of water, thus keeping the velocity low like it should be, unless your running 15 gpm through it or less.


The reason I think it is flawed is because I don't think it is ever a good idea to fill a larger pipe with a smaller pipe......if that was the only choice you had....I would have passed on the job.

We all have our opinions, my opinion is based upon 12 years of experience. I have seen many systems done in this manner and they don't always work right.

I still have a hard time believing that you got 28 gallons per minute out of a 3/4 inch galvanized pipe! That to me is the biggest shocker.

[Ground Master]

sprinkler guy what size mainline would you have gone with in this situation?

[turfman59]

Originally posted by SprinklerGuy

I still have a hard time believing that you got 28 gallons per minute out of a 3/4 inch galvanized pipe! That to me is the biggest shocker. Tony I understand what your concern is, Harold is right at 28 gpm it is not very strong pressure probably If I was to guess 20 psi at best,,, remember when I nozzle that volume down to 15 to 18 gpm is when you see dynamic pressure around 45- 50 psi.... great operating pressure for 5-6 rb 5000's with Stainless steel heads...

So are you saying you would have used all 3/4" mainline or would you have upsized to a full inch ?

By the way thanks for the great debate

[SamIV]

Hey Turfman59

Keep at it. These guys rode me quite a bit about a few of my posts. Told me I could not make money doing this solo. Most of what they tell you has some merit. Don't let the few with the bad bedside manner deter you. Just part of it.

I learned a bunch from these ever more experienced than I. We are fortunate to be able to share in their knowledge.

Sam

[HBFOXJr]

Tony, the premise is the same for for a 5/8 meter into a 1"pvc main. That is not the problem. Just say you don't trust the flow characterisitics of old 3/4" galvanized.

Maybe Mich water is different than NJ but here that pipe would be about a pencil diameter through the middle by now. I won't use a galv service for that reason. Mitigating circumstance is a 28gpm open flow. I've open flowed 1" city water svc with 1" meter @ 50 gpm. So the 28 gpm open flow may be pretty clean.

Still I would not have use it. Personally I'd have gone back the 8 ft to the main and replaced it with copper or poly out to the "T" for irrigation then coupled it back to the house galv.

Tony, You fishing and thinking about beautiful women? Hows that working for ya?

[SprinklerGuy]

The fishing is good...slowing down now cuz it has been 90 degrees the last 2 weeks with no clouds.....fires are popping up everywhere in our forests again.

As for the beautiful women...I think of my wife often.

Harold, I am going to call you again next week.....early am?

[turfman59]

I just tested it today
with the mainline at approx 210 ft away from the point of connection its doing just fine with 5 rotors using 3 gpm.

I am going to tweak and play around with it and try to get 18 gpm out of one zone....... This is exciting..... I do notice a little more weakness ( not a lot from the point of connection to the end zone.......

[turfman59]

Originally posted by HBFOXJr

Still I would not have use it. Personally I'd have gone back the 8 ft to the main and replaced it with copper or poly out to the "T" for irrigation then coupled it back to the house galv.

? that extra 8 feet would have added 650.00 to the cost of the project. Thats where the city of evart drew the line.
no charge at where I dug it up..

I think I will try to take a picture of the inside of the galvinized where I splice into it.....you will be amazed at how knew it still looks after 35 years.... but add another 90 feet on to it and that is where the friction drop comes from

[greenworldh20]

turfman,

please do not be offended by our constructive criticism... i put pics and posts up here to bounce of irrigation people...no more and no less.

i question what you did because it did not make sense to me...but i guess if i was at your project i would understand.

i still stand by my original statement...if it works and you got paid, MOVE ON.

brian

[turfman59]

I think I really made a system that is on steroids compared to the 8 gpm that was at the site to begin with,,,,, even if it is limited to 15 gpm its still twice what it was before..... Move on you bet...
I just bid a job with a 2 hp pump and approx 61 heads my biggest to date,,,,after all I am just a trunk slammer...I am going to be pumping out of a river on this job,,, I am sure I will be able to come up with something contraversial to talk ablout LOL:D

[jasond]

From my experience, I don't understand what the benefit of upsizing from 3/4 to 1.25 is. Unless you are trying to compensate for hammer, all that will occur is NOTHING.

In old strip mining operations, water pressure was created by elevating tanks above the quarry and then reducing the size of the hoses every 250 LF. That would create a head pressure at the nozzle.

The opposite would occur in your scenario. The GPH is only what the 3/4 will allow. The munincipality only has so much pressure in their distribution (which usually is in the 90-140 lbs range).

If the tap at the main is a 3/4 corp, and the copper from the corp to the meter/curbstop is 3/4, then you will only be able to 'draw' what a 3/4 will allow in GPH at the max PSI given. Also, won't the 1.25 allow for cavitation to happen? Not a huge concern, but the homeowner's domestic could be affected since the air pocket is forming between the meter and the BFP.

:confused:

[Ground Master]

shesshhhh.......its called pressure loss!

If bruce would have stayed with a 3/4" mainline (schedule 40 pipe) that say ran 100' he would lose about 15 psi for every 100' (at 14 gallons a minute).

Now, by UPSIZING to 1-1/4" pipe the pressure loss is reduced to 1.5 psi for every 100'

Also, the water velocity is greatly reduced by upsizing the mainline (at least the velocity thru the mainline portion of his system).

Your example can be performed by covering the end of a garden hose with your thumb.......you are just restricting the size of the pipe which increases pressure BUT reduces flow.

[turfman59]

Originally posted by Ground Master
shesshhhh.......its called pressure loss!

If bruce would have stayed with a 3/4" mainline (schedule 40 pipe) that say ran 100' he would lose about 15 psi for every 100' (at 14 gallons a minute).
flow. exactly, but remember all I had was 8 gpm, because it was flowing through almost 100 ft of 40 year old galvinized pipe. after the meter and backflow preventer the working gallons per minute was about 6 - 7 gpm. HUGE lawn the window to water would be into the daytime hours to get it all done ET rate was too high in JULY and August to effectively get it done... is this making any sense to you yet ? Its a quality product that was produced, not a hurry up get it done and move on job.



MY question is what size main would you have used with over 210 feet of distance from POC to the last valve, I have a feeling that someone is blowing smoke.... you would not beleive this when it turns on and runs, Iam getting 38 ft distance with RB 5000's with 3 gpm nozzles on 5 heads at a time.

ITs a quality product
RB 5000's Stainless
Hunter 1 .25 jar tops
pro C controller
rain click
and a 1.25" main

when this thing comes on the water really flys, and the customer has a grin from ear to ear...LOL

[turfman59]

Originally posted by jasond
250 LF. That would create a head pressure at the nozzle.

The opposite would occur in your scenario. The GPH is only what the 3/4 will allow. The munincipality only has so much pressure in their distribution (which usually is in the 90-140 lbs range).



:confused: when you reduce 90 feet of galvinized you are in effect allowing more water to move through that 3/4 " inch pipe. what are you relating the 90 to 140 lbs to ? feet of head or psi are system runs at around 65 -70 psi......

You are doing a great job of making my case for me

[Planter]

Originally posted by Ground Master

Your example can be performed by covering the end of a garden hose with your thumb.......you are just restricting the size of the pipe which increases pressure BUT reduces flow.

I am not very good at this, but I think if you have a static pressure of, say, 50 PSI there are only two ways to increase the pressure: 1) Elevation drop from the point the static was taken at .433 PSA per foot of elevation drop or 2) Increasing the pressure through pumping. If I understand this correctly (I may be wrong, that's why I'm asking) reducing the outlet port size, as in placing a thumb over the end of the hose will not raise pressure, but will increase the velocity as the opening is smaller. My thinking is that it is much like running flow through pipe. The water will move more slowly in a larger diameter pipe. We have energy in pressure and velocity. Making the outlet port smaller does not change the pressure, it changes the velocity of discharge. Same pressure, just moving the water faster.

Am I wrong in my thinking? I have often wondered about this. Can any of you more experienced guys explain it to me?

Thanks!

[HBFOXJr]

You are entirely correct. Nothing else need to be said!

[jasond]

Originally posted by SprinklerGuy
nope...if you understand it then no need to elaborate.

Did you though feed the 1.25 inch main with 3/4 inch galvanized?

Turfman, You answered 'yes' to this question.

I guess I am confused. You can only fit 5 lbs of potatoes into a 5lb sack. What your describing is like putting 8.3333 lbs of potatoes into a 5lb sack....it doesn't't work (the math is correct).

If this were electricity, it would be silly to use 14/3 wire 8 ft off the pole, and then run anything larger...let's suppose 00 gage, to the house. The only amperage that you would be able to draw would be what the 14/3 wire could capacitate. Of course, with electricity, the 14/3 wire would act as a fuse, and melt.

Same scenario applies to your irrigation system. You can only benefit from what the 8 foot 3/4 line (from the main to the T you installed) will capacitate. Since this is fluid dynamics, the pipe won't melt.

If you wanted a 1 1/4 line, why didn't you just dig another 8 ft and remove the 3/4 inch corp-stop (which only has a 3/4 tapped hole in the ductile iron main...I am assuming DIP is in place) and replace it with a 1 1/4 tap, corp-stop, 8 ft of 1 1/4 copper, 1 1/4 tee, and then reduce the domestic to 3/4 and leave 1 1/4 to the irrigation meter/system.

Justa wonderin?!?

[turfman59]

Originally posted by jasond
Turfman, You answered 'yes' to this question.


If you wanted a 1 1/4 line, why didn't you just dig another 8 ft and remove the 3/4 inch corp-stop (which only has a 3/4 tapped hole in the ductile iron main...I am assuming DIP is in place) and replace it with a 1 1/4 tap, corp-stop, 8 ft of 1 1/4 copper, 1 1/4 tee, and then reduce the domestic to 3/4 and leave 1 1/4 to the irrigation meter/system.

Justa wonderin?!? you need to read the whole thing,
not just start in the middle of the thread,,, to dig another 8 ft would have costed $ 650.00 extra. I was only getting 7-8 gpm at the house. however I now have 15 to 17 gpm a minute at approx 42 -48 psi dynamic pressure. A short piece of galvinized will flow 16 gpm if it is a short piece. especially when there is a 10 ich main behind it....

[Without A Drought]

has anyone ever done a water service? around here a plumber can increase service from the curb stop on to the house. following that install. ,he may then request the h20 company change the service from the city main to the stop. this is a similar situation. pressure does not get signifacantly boosted, but GPM is increased. the 8' or so of 3/4" is almost negligble in terms of GPM. Turf, you were right in what you did. Continuing in 3/4 would have resulted in higher velocity, worse hammer, and LOWER GPM!

pg

[Dirty Water]

I never read this thread.

Sheesh....I don't know what to say about some of the guys on here (or at least used to, I have'nt seen many of them for a long time).

We deal with 5/8 meters all the time, also lots of taps of 3/4" service lines, and we still run 1" mains....it doesn't matter if the distance between the service line and the main feed is short.

Worst case scenario your water velocity will be slightly higher.

[Wet_Boots]

(shouldn't old threads lie still and undisturbed?)

Anything involving the breaking of pavement, to get at a water main, is pretty extreme. Assuming official cooperation, and a nice fat check from the homeowner, a separate water main tap and meter can really make a difference on a large property.

Short of that, and assuming exquisite timing and cooperation all around, one can add a special 'flare bushing' to a standard curb stop (the flare type, for copper tubing) and then connect larger sizes of copper tubing, and a larger meter in the house. For a home a hundred feet or more from the street, the supply line to the house is the source of the most pressure loss.

The timing part is because this has to be done when the home is under construction. The street taps will already be in place, and someone (you) has to be there with the non-standard supply line and curb stop bushing, because this isn't going to happen if you aren't on the site and ready to make it happen. (Witness the number of threads about undersized water supplies)

[PurpHaze]

I vote for 3" domestic main lines to all residentials. :laugh:

[Wet_Boots]

I remember one house that had a 2-inch meter, and the sprinkler system was one zone, with a brass zone valve in the basement.

[Dirty Water]

I vote for 3" domestic main lines to all residentials. :laugh:

seconded, case closed.

[WalkGood]

Worst case scenario your water velocity will be slightly higher.



Just wondering..... if the water velocity is higher flowing through that old galvanized 3/4" pipe won't it cause erosion inside the pipe?

[PurpHaze]

Galvanized pipe is a funny creature. You can take pipe that has been in the ground the same length of time (let's say 30 years) and there are numerous factors that will have an impact on corrosion, both externally and internally. I've seen wrapped pipe that is clogged inside and unwrapped pipe that is clean as a whistle. I've seen unwrapped pipe that is externally sound (after knocking off crusted rust) and wrapped pipe that just breaks or crushes when trying to unthread it with a pipe wrench. Guess it depends on the quality of the water running through it and the type of soil it's buried in.

[WalkGood]

Galvanized pipe is a funny creature. You can take pipe that has been in the ground the same length of time (let's say 30 years) and there are numerous factors that will have an impact on corrosion, both externally and internally. I've seen wrapped pipe that is clogged inside and unwrapped pipe that is clean as a whistle. I've seen unwrapped pipe that is externally sound (after knocking off crusted rust) and wrapped pipe that just breaks or crushes when trying to unthread it with a pipe wrench. Guess it depends on the quality of the water running through it and the type of soil it's buried in.

That makes a very good argument for NOT running a much higher velocity thru the subject 8 foot section of galvanized pipe.

[HooKooDooKu]

Isn't this thread old enough by now the galvinized pipe being discussed has since corroded away and been replaced?:laugh:

[Currier]

Just like public education. Everyone has an idea on what is right....and everyone else is an idiot. Does it work? Will it work for 10+ year or more?


On one hand your a hero, on the other a schister. You decide for your business where you fit and don't worry too much about the rest.

[PurpHaze]

Isn't this thread old enough by now the galvinized pipe being discussed has since corroded away and been replaced?:laugh:

LOL... An astute observation from an engineer. In reality some galvanized pipe will be dug up by archeologists in the future and the first thing out of their mouth will be, "What the heck?" :laugh: