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bayaa
01-20-2002, 03:00 AM
I have been told that you should have your main line one size larger than your laterals. If this is correct why so and what if your poc is 3/4 and you want to you 3/4 laterials. Also what should your sprinkler valve size be the size of the main line or the laterials

HBFOXJr
01-21-2002, 02:26 PM
Main lines and laterals are sized according to required flow in GPM, and allowable friction loss. There are NO rules regarding the size of the main vs. laterals. Since yuou didn't know this you probably shouldn't attempt what ever is on your mind. If it is a curiosity question fine.

But in any case, if your gonna do something, go take some design classes. A sprinkler system done as it is supposed to be, is engineered, not just put together. There is a lot to know.

bayaa
01-26-2002, 08:35 AM
hey buddy,
I've never tooken a class yet in sprinklers but havent had any problems or dry spots I think you use take a class in .......

HBFOXJr
01-26-2002, 08:46 AM
for being a little hard nosed. Here in NJ I find people all the time selling things they don't know jack about and messing up systems. I do 10's of thousands of $ in repair and alteration work on systems installed or repaired by those that have not studied design engineering. This season is my 31st. being self employed.

Although I do apologize for the personal assumptions I do stand by my irrigation statements!

SprinklerGuy
01-26-2002, 09:45 AM
Hey HB, that was a little rough, why don't you try being a little thankful for the people who do it wrong! How else are you going to do 10's of Thousands in repairs/renovations? I know I am thankful that there are many LCO's and homeowners who do it themselves. Without them, my companies growth would be stymied a little.

bayaa
01-27-2002, 03:42 AM
In my area the water meters are all 5/8 or 3/4 but im only have done Residential homes. I just saw something on the internet about you should use one size up from your laterials and i know im not going to ever use 1/2 inch laterials. Just want to know if i should investgate any futher in this and yes I already know I should take a few class but I do not have the time at this point. I can say I havent screwed sprinkler system up yet but I do want to learn more.

HBFOXJr
01-27-2002, 12:57 PM
To make life easy we use nothing smaller than 1" pipe for main and laterals.

Our meters go from 5/8 to 1" standard and water pressure from from the 20's to 80's of pounds. We do lots of private wells with pumps from 1/2 to 3 horse and ponds lakes and streams with 1-3 horse pumps. I'm talking residential.

Go to the hunter website and download their residential sprinkler system design handbook or order one or get one from a distributor. It is an excellent place to start on your own. And don't change what they tell you to do because some counter guy or other no nothing says youdon't have to do that!

Just because you think you haven't screwed anything up diesn't mean you built the most effective or water efficient or cost efficient system. There is a ton to know about soils, precipitation rates and more. Hunter also has many other publications available and there is good info in their catalog.

turfman59
01-27-2002, 05:21 PM
Mr Fox
it seems to me that you are in business to do quality work. I commend you for your responses on this site. But because of guys that are do it yourselfers at heart and decide they can do this as a business you generate 10k in business volume fixing there mistakes. Why would you knock it seems to me your making a decent living from it. It is nothing more than entreprenurial spirit ... Thanks again for all the great posts
SSSSSEEEEEEEEEE ya

HBFOXJr
01-27-2002, 07:22 PM
It's a character flaw. Your right, I should kick'em while they are down or keep my mouth shut. Instead, I hate to see customers bamboozled by contractors doing things out of ignorance bordering dishonesty. But it seems like the two are happy together, so who am I to say these two parties can not wed.

Guess I figure if I can save a few guys from themselves, improve the industry and it trickles down to the consumer, my life isn't totally wasted.

bayaa
01-28-2002, 01:45 AM
well this current job im doing the water meter is 5/8 and has about 110 psi. What size pipe (main line laterals) would use and what size valves. From the poc to the furthest head is about 120 feet.

HBFOXJr
01-28-2002, 06:56 AM
1" everything and a pressure regulator to match the zone flow.

SprinklerGuy
01-28-2002, 11:31 AM
I'll bet I know the next question.....what is zone flo.......?

HBFOXJr
01-28-2002, 04:32 PM
Now stop that Tony, behave yourself.

Hey what are we doing about service contracts?

bayaa
01-29-2002, 03:55 AM
Im going with one inch valves then reducing to 3/4 laterals. I say that the zone flow is what the pressure that is need to operate the heads that one is using for optimal performance

SprinklerGuy
01-29-2002, 08:46 AM
Actually, the flow is the GPM of ALL HEADS on a zone. GPM is gallons per minute. Each head that will be on a zone should be added up and totalled. The total GPM should not exceed the capacity of the pipe used.


Harold, I am going to send you a copy of the service contract I just put into play. I sent my newsletter out 1 week ago and I have already signed up 5 contracts! I actually plajorized someone elses, should work good though~!

aquaturf
01-29-2002, 06:58 PM
We do everything with 1" line, and you may even consider 1-1/4" main lines for pressure that high. What kind of volume are you getting at 110 psi? That is quite a bit of pressure for a residential job.

HBFOXJr
01-29-2002, 07:25 PM
What does main size have to do with pressure?

SprinklerGuy
01-29-2002, 10:48 PM
"what kind of volume are you getting at 110psi?"

What volume do you want!!!!

Geez........Can you believe this Harold?

Planter
01-30-2002, 01:51 AM
The limiting factor on the flow is going to be the meter size. Over-clock the meter by trying to pull more flow through it than it can handle and the water company will be chasing you down to pay for a replacement.

Additionally, the service line size will also be another limiting factor.

It is generally not a good idea to drop down in size to a lateral line smaller than the size of the valve. I have seen the cheaper valves that don't want to turn off when this is done. Using a 1-inch valve and dropping right down to a 3/4 inch lateral is an example. 3/4-inch line, as a rule of thumb, will only handle about 9 GPM, which is about not a lot of flow and will severely limit the number of heads you can safely use. Valves can flow enough water to handle one nominal size larger pipe than the size of the valve, i.e., a 1 Ĺ-inch valve can handle the flow from a 2-inch line.

Hope this helps.

Hydraulics is a science and we have all seen systems messed up by poor hydraulic engineering.

Bayaa, I'd recommend you take a class or at least get a text on design. If you canít take a class you may want to get one of the design books offered by Rainbird or Hunter for professional installers, study it and ask questions.

SprinklerGuy
01-30-2002, 06:59 AM
It is generally not a good idea to drop down in size to a lateral line smaller than the size of the valve. I have seen the cheaper valves that don't want to turn off when this is done. Using a 1-inch valve and dropping right down to a 3/4 inch lateral is an example. 3/4-inch line, as a rule of thumb, will only handle about 9 GPM,


Planter, I'm sure there are classes in your area of the country too.

The quote above is wrong........Are you saying we should size our valves to our laterals? That's what it appears you are saying. LImiting the size of our lateral lines to "1 size above the size of the valve" would not be the answer. As for the valve not shutting off, it is not because it has a 3/4 line hooked to it. Do you think the valve realizes this? Do you know what a "flow control" is? Also, 9gpm is a little conservative for 3/4 pipe.

I am all for giving advice at this site, however let's make sure the advice is good.

HBFOXJr
01-30-2002, 07:28 AM
OK Tony, you can go to 10 gpm on the 3/4 if it is class 200. Over that you'll exceed a 5ft/sec velocity. Velocity, thats a big word. Tony do you think some people can say velocity? If your sched 40 3/4" your down to 8 gpm to stay under 5 ft/sec.

I think valve closing is related to manufacture. Some are just better than others. Some manufactuers recommend closing the "flow control" till head performance visually diminishes and then open up one turn.

SprinklerGuy
01-30-2002, 09:59 AM
VELOCITY

Hey you're right...it is a big word. Like you have said before Harold, should be careful who we give advice to here and what advice it is. Without the proper background in hydraulics and system design etc......information given in small bites like we sometimes do here....can be very dangerous.

bayaa
01-30-2002, 02:58 PM
So is ok to use one inch vavles and use 3/4 inch laterals

HBFOXJr
01-30-2002, 03:12 PM
What's your Calif lic number? You are licensed, right?

aquaturf
01-30-2002, 06:30 PM
Hey Bayaa,

No - don't use 3/4" line. In fact, you may want to walk away from the job, and do some easier ones before you try to tackle pressure like that. However, if you decide to continue:

Given your pressure of 110, which I am assuming is the static pressure (no water running), you should use 1" laterals. Of course, once you flow water, the pressure will drop as more water flows (residual pressure). You should know what your residual pressure is at your desired flow rate. In other words, if you are looking for a flow of 10 gpm, what is the pressure (psi) at that flow?

I am no engineer, and certainly not as talented as our two egotistical ("big word") professors on this board, but I will give you the best advice that I can. If you use 3/4" pipe you may have problems with high velocity, which can cause water hammer when the zones open and close. The larger diameter your pipe, the less velocity you are likely to develop, everything else being constant. Thus, I would suggest 1-1/4" mainline with 1" laterals so that water hammer will be less of a problem. Remember, water hammer is a chronic problem - your system may be working fine when you leave the job, but hammer can slowly weaken pipe and fittings in the future months and years.

Like I said before, your pressure of 110 psi is of concern to me, and is quite high for residential. You may want to use some type of pressure control device, I have never used them.

HBFOXJr
01-30-2002, 07:45 PM
You need design and engineering training before handing out advice. If you can't run with the big dogs, stay on the porch!

bayaa
01-30-2002, 07:48 PM
Aguaturf,
thank you for the advice it has helped a lot. Also to the other members of this fourm thank you for some of your advice.
I will for sure use a pressure reducer and I'm trying to learn more about water hydruils that is why go to this fourm. Sometimes you got to learn as you go to pay the bills .

HBFOXJr
01-30-2002, 07:54 PM
2 or 3 days of basic design is all you need to get started . You won't have it memorized but you'll be aware of all that goes into smaller residential & commericail systems. It takes about 5 years to make a good sprinkler man around here. Thats because all the little things change from job to job and you need 5 years exposure to cover a variety of stuff. Don't tell us you can't take the time. If your committed you make the time.

HBFOXJr
01-30-2002, 07:56 PM
did you get the Hunter design book yet. Are you licensed?

Chuck Sinclair
01-31-2002, 01:53 AM
bayaa

Check this out see if it helps you Learn:
Irrigation Manual (http://www.hunterindustries.com/Resources/pdfdocs/domestic/LIT194w.pdf)

BTW are you licensed? you need a C-27 Contrators license in California to do irrigation.

YES i am Licensaed #798016

SprinklerGuy
01-31-2002, 07:35 AM
Man I wish I lived in MA so I could make a little money fixing systems up there. I hear there is a guy up there designing sprinkler systems and basing the pipe size used on pressure! And he thinks he can slow down the velocity of the water by using bigger pipe!

I have an idea! Since you are using 1 1/4 mainline coming off of what is probably a 5/8" meter, why don't you max out the valves too. Hey I know, why not use 1 1/2 inch valves, 1 1/4 inch laterals and push about 30 gallons per minute (or more) on each valve. Using your logic there will be no velocity, no water hammer, and the lawn should look great.

Aqua, I am sure you are a talented man and good at what you do. But, before you join the ranks of the irrigation professionals, perhaps you should do some studying. HB has 30 years on ya and I have 20. No offense to ya, sure you are trying to help.

Baaya, I'm sure if you wanted to know exactly what to do, you could email all the pertinent info to either HB or myself and we could help. So far you have not given us enough. There is more that needs to be told prior to designing a system. Much more. I will be glad to help, if you give me all the info!

Nice to see ya over on the dark side Chuck!

Chuck Sinclair
01-31-2002, 10:50 AM
Tony,

I have been here all along, been following this thead since the start and LMAO real ineresting some of the advice you can get here (If you follow it could lead to trouble)

HBFOXJr
01-31-2002, 11:05 AM
And when you give good advice and places to learn and get info you get trashed.

SprinklerGuy
01-31-2002, 12:14 PM
Cmon HB, who would trash you? Let me at 'em..............

motivated1
02-04-2002, 11:45 PM
Look who cares about 110 psi? it only takes 30 @ head to make the things do what the mfg'r in calif says their going to do @ 30 psi! @ 110 psi your going to try to have a cold water miser in these peoples lawn. Look take a Hunter cat. or even a weathermatic, or Rainbird for sakes look at the tech specs in the back! I don't rmember if it shows loss thru meters or not. Whatever it says only design the system @ 60% of that capacity. Who cares if it's 1" 1.25" or 1.5" main line! Go 1.25" as avg. for anything up to 80psi. I knw psi doesn't matter, psi i just guide to start. Flow, gpm's, static pressure, and dynabic prssure, rate of flow, and friction loss. these are thing yo need to understan to truly design an efficient system. So when a custome asks you how long should I water? YOU say hmmmm...your Precipitation rate is this... yoursoil is this... so you should water about an inch per wk so.... water this long tis many times pre week! There. As far as laterals go... pipe size depends on how mush water is actually flowing through that specific peice of pipe once the system is engaged. YOu can install an entire system w/ just 1/2' if you wanted as long as the flow of water through that pipe does nt exceed it's capcity. That' my soap box! My wife's 7mos prego and now i have nothing else to do in my extra free time! SO......go get some education like I did!
motivatedmaintenance.com (http://www.motivatedmaintenance.com)

bayaa
02-05-2002, 01:50 AM
You know in all truth ireally wish i never asked the question. My system runs great no water hammer great coverage. Also picked the neighbor next store for a new lawn and sprinkler system this sytem I'm using 1/8 inch mainline with 1/16 laterals think it will work?

Planter
02-05-2002, 06:02 AM
I'm sure it will be.:)

Chuck Sinclair
02-05-2002, 11:23 AM
You never answerd the question are you License?

HBFOXJr
02-05-2002, 12:48 PM
Chuck, the silence is deafening. :D

Chuck Sinclair
02-05-2002, 04:01 PM
Originally posted by HBFOXJr
Chuck, the silence is deafening. :D

Yes i know the silence speaks volumes!! :eek:

motivated1
02-05-2002, 06:18 PM
sure, 1/8" will work 1/16' will work for laterals. GO ahead put 4 or 6 heads on there. Make sure you have @ least 42 psi and you buy a 3/4' valve for every head installed, plus bushings,plus couplings. Hey....! why not make it a sub surface irrigation system then you could do it w/ 2 valves and still use your 1/8# or 1/16# C'mon people tel's be a little more sarcastic! 1/8 1/16 pipe! geeeeess! ...not to be the biggest...striving to be the Best! (http://motivatedmaintenance.com) Matthew Mc Menamy T X L I # 8050

Ground Master
02-20-2002, 02:19 PM
Where I'm at 99% of homes have a 5/8meter and 3/4service line. I use a 3/4 x 1 bull nose tee at the tap and run 1" everything rest of way. Max gpm of any zone is 12, like to stick to 10. This keeps pressure loss at a minumum and water velocity low---2 keys to a reliable system.

Silver Bullet
03-12-2002, 07:48 PM
When you guys talk about psi, you talk like that is the only thing that matters, compared to volume. I am not writing this because I think that I know everything about the irrigation industry. I talked to a Hunter representative that told me a story about a system that was put in at an older house that had galvanized pipe that was half plugged because of corrosion. He said that they tested the pressure, and it had great pressure, but didn't have enough volume of water through the pipe to make the system work.

Planter
03-13-2002, 02:21 AM
Originally posted by Silver Bullet
When you guys talk about psi, you talk like that is the only thing that matters, compared to volume. I am not writing this because I think that I know everything about the irrigation industry. I talked to a Hunter representative that told me a story about a system that was put in at an older house that had galvanized pipe that was half plugged because of corrosion. He said that they tested the pressure, and it had great pressure, but didn't have enough volume of water through the pipe to make the system work.

True story!!

Pressure and volume of flow are two of the main issues in setting up a good system.

K

Jayusl
04-17-2002, 08:02 PM
I'm curious to know why no one has mentioned elevation changes and there relivence to static pressure. Surely professionals with 50 years of combined experience have more important things to do besides trashing and humiliating site members with less "experience." I'm sure we all have seen companies who have been around for decades doing mediocre work. Spend less time talking and more time studying.:blob2:

HBFOXJr
04-18-2002, 07:32 AM
I'm curious to know why no one has mentioned elevation changes and there relivence to static pressure. Surely professionals with 50 years of combined experience have more important things to do besides trashing and humiliating site members with less "experience." I'm sure we all have seen companies who have been around for decades doing mediocre work. Spend less time talking and more time studying.

We haven't mentioned elevation differences and how it can affect static pressure, because in most cases it will not affect pipe sizing which is the topic of discussion here.

Static pressure differences due to elevation elevation would be dealt with as having too much pressure requiring regulation or not enough and requiring a booster pump.

Jayusl
04-18-2002, 08:47 AM
Mr. Fox,

I am not going to write a long explanation for your benefit, but for the benefit of the people posting to this board looking for information. You made an excellent point earlier in this thread when you recommended that anyone looking to install irrigation should take some sort of design training. I will take that one step further. Anyone who installs, designs, or REPAIRS irrigation should take some sort of training on basic hydraulics. Most major manufacturers sponsor one or two day classes at their facilities or at your local distributor. Your job will be considerably easier if you understand how predictable water "behaves."

Anyway the point I was trying to make with my earlier post was to try to get you guys to explain elevation loss. I promise I will get to that later but first lets step back for a minute. If I remember correctly the pressure at the POC was 110 psi. Lets think about where he got this number from. Assuming that he is referring to his static pressure readings, he probably landed on this number by checking the hose bib connected to the main on the side of the house with a threaded pressure gauge. Now we would have to consider a lot of different things before I would feel comfortable with designing the system around this 110 PSI reading. The pressure in the city water supply fluctuates at different times of the day because of public usage. You may get 110 Psi at 10:30 A.M. and then check again at 1:00 when everybody is flushing toilets in the city after lunch and you might get 85 Psi. Maybe your homeowner gets up and takes a shower at 5:00 A.M. while your system is running. My point is to determining an accurate static pressure figure you have to take several measurements at different times of the day and on different days of the week. Your local water purveyor can provide you with information on average city main line static pressure readings on the site. Only after all this info. is collected should you move on. Systems have to be designed using "worst case" figures to be able to keep up with the demand of high end landscapes year round.

I will stop here for now so I can back to work.
I will continue this post later

David Gretzmier
04-21-2002, 12:05 AM
sheesh -this is an amazing thread. having done this for about 10 years, heres what I know about pipe sizes in my area- 95 % of irrigation systems we fix or install run fine on 1" main, 1"- 3/4" laterals, and 4-5 rotors or 8 pops on each zone. period. you can grouse all day long about friction loss, volume, velocity, and all the yadda yadda, but the reality is this- most guys out there only check that stuff when pressure is below 45psi at the meter, or when making a long run. we use 1"mains and lats now for ease of install, and it covers 90% of installs we do. If pressure is over 90 psi, we regulate w/ adjustable in a box to adjust up/down in future if necessary.I have taken the classes and read the books and can quote stats like 5ft per sec. if you like. the sad reality is all folks don't know what the system is gonna do at 6 in the morning when everybody on the block starts taking a shower, or when they add 16 houses to the 2" main on the street you hooked up to 2 years ago. you build headroom in a system and don't max out anything in those graphs on pipe sizing in the rainbird and hunter manuals. I guarantee fox and all you guys made mistakes when you started out and don't throw stones at the guys who are trying to learn. help them. and be nice. Dave g

bayaa
04-24-2002, 04:26 AM
Hey im the guy that started this post and I agree with the last guy. It seems that a lot of you guys are acting like your build a dam orrunning a nuclear power plant. Dam it was just a simple question but I did read the hunter book. I believe that you do need to know alot about pressure loss and inches per seconds in some cases. Have you ever though that the comanys pushes larger size pipe because it cost more but probaly cost them the same to make. Because I know I rather buy 3/4 parts than lager sizes when it comes to price.