PDA

View Full Version : Using river POC for first time.


jcom
02-19-2007, 10:47 AM
What do we need to avoid for our first river source install? Should start in a couple of months.

A fast moving, relatively clean river needs what type of filter?

Using a 70 gpm pump with a looped 2" mainline with 1" laterals zoned at 50 gpm. PGP's and MP rotators for heads.

We have only one blade for our 255sx. Can we pull 2" if we use additional pulling power in the form of ATV?

Thanks for the opinions and ideas in advance.

John

Dirty Water
02-19-2007, 10:59 AM
50 gpm through a 1" lateral? Your looking at a velocity of 14.43 FPS. Your not supposed to exceed 7-5 FPS.

Are you nuts?

A looped 2 inch mainline moving 35 GPM (Because its looped) has a velocity of 3.092 FPS, which is safe, but I'd go up to 2.5" because your going to be losing close to 1 psi per 100' feet.

Have you ever worked with big pipe/large zones before? Your idea is crazy, is this a joke?

Second, rent a trencher. Or get a bigger plow (410sx with a trailing bullet still has trouble with 2").

Finally, what is going to happen to the 20 GPM difference between what your using in your zone and what your pumping out of the river?

PurpHaze
02-19-2007, 11:24 AM
A looped 2 inch mainline moving 35 GPM (Because its looped) has a velocity of 3.092 FPS, which is safe, but I'd go up to 2.5" because your going to be losing close to 1 psi per 100' feet.

The engineering premise on looped main lines is that generally a looped main can be made one size smaller because the flow will be split between the two directional sides of the loop supplying a valve. His 2" main line could therefore carry 70 GPM within the 5FPS standard. Additionally, looped main lines allow for less pressure loss at a given point due to the water travel profile.

That being said, I still size looped main lines as if they were a standard dead-head main based on the total number of valves (GPM) to be activated off that main line simultaneously. It allows a buffer in the event that things change in the future and additional zones have to be added.

Dirty Water
02-19-2007, 11:29 AM
The engineering premise on looped main lines is that generally a looped main can be made one size smaller because the flow will be split between the two directional sides of the loop supplying a valve. His 2" main line could therefore carry 70 GPM within the 5FPS standard. Additionally, looped main lines allow for less pressure loss at a given point due to the water travel profile.

That being said, I still size looped main lines as if they were a standard dead-head main based on the total number of valves (GPM) to be activated off that main line simultaneously. It allows a buffer in the event that things change in the future and additional zones have to be added.

Agreed, though I thought I specified this in my original post? Its always weird when you have zone lines larger than your looped main coming out of the valve :)

Regardless, I don't think jcom should attempt this until he does a little reading.

PurpHaze
02-19-2007, 11:36 AM
Its always weird when you have zone lines larger than your looped main coming out of the valve :)

That it is. But that's the nature of using looped main lines in certain applications. :)

Regardless, I don't think jcom should attempt this until he does a little reading.

From what I'm reading I'd agree. He needs to step back a little and either do the reading or have a qualified designer get involved.

jcom
02-19-2007, 12:18 PM
This is my first with bigger pipe. My plan was to use 2" fittings and 3-4 1" laterals per 2" valve.

I have a couple of months to learn what I need to and am starting with input from you folks. The layout I have in mind will use approx. 500' of 2" pipe in mostly sand and was hoping to avoid additional equipment rental. Hence the extra h.p. on the 255sx..

We are looking at a lift height of 30'. Or is this "feet of head".

I hope I am not nuts,:rolleyes: but merely trying to get my feet wet.

Any recommended reading sites, books, etc. is appreciated.

John

Wet_Boots
02-19-2007, 12:50 PM
You can't lift the water thirty feet, if you're talking about elevation on the suction side of a pump. How much acreage is being covered here? Is there an old thread on this install?

jcom
02-19-2007, 02:50 PM
We will push the water 30' up at the highest level. The pump will be within 5 ft. of the water.

I posted lst year on this project but did not get the contract until after freeze up here. Now am trying to put together a final plan so am looking for ideas as to what I need.

The total coverage area is about 1 1/2 acres I would guess.

The homeowner has had the electrical work done already. I will have to hook up the pump start and timer but the pump power is in place already.

Thanks again for all the help.

John

Wet_Boots
02-19-2007, 03:08 PM
I thought this was a familiar situation (http://www.lawnsite.com/showthread.php?t=152335) ~ basically, you need to clear up any confusion about using the owner's old pump. Like looking him straight in the eye and asking him if using that pump is worth the system costing at least a thousand dollars more. If he's handing you a blank check, then go for it, and have fun. Otherwise, get a useful pump for that system, and work from there. Earlier suggestions would allow much smaller pipe sizes, that you can easily pull.

jcom
02-19-2007, 06:04 PM
The homeowner does want to use his pump. Says he has a relative nearby using the same thing and it works well. Probably a good idea to go have a look at that system. Sounded like it also had a looped mainline of some type.

I bid the job high so I have some fudge room built in as to costs, etc..

Probably have to fly one of you gurus out for the project.

John

Wet_Boots
02-19-2007, 06:21 PM
As long as you're getting the money, then what the hey. You won't have the pressure a jet pump or a multi-stage will offer you, so you just have to live with lower operating pressure, and less distance between heads, and more heads, and increased material/machinery costs. You may wind up paying more than the costs of a new pump, in order to work with the one that's there.

By all means look at the other system, with an idea to copy anything practical you observe.

Sight unseen, I might look at river water as one occasion where impact heads can have superior performance. No question, at low operating pressures, the much-maligned Rainbird Maxipaw impact will probably spray further than anything else you can find.

PurpHaze
02-19-2007, 06:25 PM
The homeowner does want to use his pump. Says he has a relative nearby using the same thing and it works well. Probably a good idea to go have a look at that system. Sounded like it also had a looped mainline of some type.

Seeing the other system might give you a heads up if it's properly working.

Go to the Hunter site and download the "Handbook of Technical Irrigation Information" which has some good pump info in it near the beginning. It seems to be precisely what you're planning (pulling water from a lake).

http://www.hunterindustries.com/Resources/PDFs/pdf_english_misc.html

I bid the job high so I have some fudge room built in as to costs, etc..

Good... you may need it if you have to make a bunch of changes.

Probably have to fly one of you gurus out for the project.

Jerry's probably closest.

Dirty Water
02-19-2007, 06:43 PM
I'll come out for $275 an hour.

PurpHaze
02-19-2007, 06:50 PM
But aren't you in Geek Heaven??? :p

Dirty Water
02-19-2007, 07:34 PM
Actually, at the moment I'm home in sequim trying to get things packed and battling off that nasty flu that has hit the Seattle area. I feel like absolute poop and I have to drive back to Kirkland tonight and go to work tomorrow.

I'm posting on lawnsite because I need a break.

PurpHaze
02-19-2007, 07:40 PM
Cover your mouth when you keyboard please. I'd hate to catch something from you over the 'net. :)

Dirty Water
02-19-2007, 07:42 PM
Heh, its scary, as two kids have died from this thing in seattle in the last week, and my 3 year old has a fever now.

I'm keeping a close eye on her and making sure she stays hydrated.

koster_irrigation
02-19-2007, 09:21 PM
"Noteworthy Points"

-Fast Flowing River

-1" Laterals @ 70gpm

-255sx with help from an ATV

-70gpm though 2" pipe

-"What do we need to avoid for our first river install"

All of the above.

Wet_Boots
02-19-2007, 10:32 PM
I've co-existed with over 50 gpm through a (thankfully short) distance of one-inch poly, because it was already in place under concrete, and I could live with a few psi of loss, since I was splitting the line at least three ways once I had access to the downstream end of the run. But all over a 50+ gpm system? Phooey!

If the contract has been signed, and the deposit paid, then the job's a go, all other details aside. If the property layout allows for rotors only spraying 25-30 feet, then no big deal with a low-pressure pump. Otherwise, it's a big stinking deal, and on my dime, the old pump will just stay right where it is, and I provide a new one, and live with less than 30 gpm for the acre plus, and enjoy 35-40 feet from the heads, and a big savings in material, that could buy a new pump a few times over.

Wet_Boots
02-20-2007, 01:14 AM
By the way, if a relative has the same pump, then the existing one might best be saved as a replacement for the other old one. Given that you are looking at watering some areas over 100 by 100, you want some real pressure in the system. The old pump may not even be capable of as much as 50 psi. This is where you might want to observe an identical pump in action, if that's what the relative has. It might be an instance where a single-stage pump is running way out of its peak efficiency range, in order to deliver higher pressure. Many systems work that way, even though it wastes electricity. That 'wastes electricity and money' argument might sway the homeowner about the old pump.

If I had to do a surface water system on an acre-plus, working with a 255sx plow, I'd use the Goulds J15S jet pump (http://www.goulds.com/pdf/BJS+.pdf) mentioned in the earlier thread, and design for 25 gpm or so. Long runs might use less, to allow for pressure loss in a main line. If you could pull 2 inch poly for a mainline, then you're golden, and don't even need to loop the main. One might even live with unlooped 1 1/2 inch, if the flow is slightly reduced. No way are you pulling one inch line for laterals, even if you go with a smaller pump. Start a 25 gpm lateral with 1 1/4 for a minimum, and that's assuming you're having a head branching off right at the valve.

One possibility for a 25-30 gpm system to get by with (mostly) one inch laterals is for a mainline to run straight down the middle of your zones, in those rectangular areas you mention. Then you can have half a zone run one way from a valve, and the other half run the other way. That might mean some extra mainline pipe, but the simplification might be worth it.

PurpHaze
02-20-2007, 09:17 AM
Speaking of split laterals I have a couple of pictures somewhere where that LameScape company did something like that but in a little different manner. They had a 1-1/2" lateral line that went under a sidewalk. Instead of boring the 1-1/2" line they split it into two 1" lines, ran those under the sidewalk and then reconnected them to a single 1-1/2" line on the other side. I'm assuming it was easier for them to bore the two smaller lines instead of the single larger one. :rolleyes:

jcom
02-20-2007, 11:48 AM
I had planned on teeing off the 2" valve to 1" laterals. 3-4 per valve. Keeping the gpm at 15 per 1" line.

The Goulds pump referenced by WB looks like a sweet unit for this application.
It may be an option if I don't like the looks of the companion system.

John

Wet_Boots
02-20-2007, 06:57 PM
You probably won't have enough pressure on that original pump to try any shortcuts that cost you pressure. I like those Goulds jet pumps because they are very good at holding their prime, due to an internal diaphram that holds water in the case. Also, the jet pumps don't create pressures so high they can blow a poly pipe, if a valve downstream fails to open.

Among other pumps to consider are a Goulds HSC-20 (http://www.goulds.com/pdf/BHSC.pdf) or a Berkeley/Sta-Rite SSHM-2 (http://www.starite.com/specs/berk_b2094bk.pdf) ~ note that the Goulds HSC-20 doesn't have the raised suction inlet or inner diaphragm of their jet pumps, so priming and air-handling will be different. The SSHM-2 looks to be an advance in bang for the buck, but I've never used one, so I don't know how they hold up. Goulds are built like tanks. Any of these pumps figure to cost at least five hundred bucks.

jcom
02-20-2007, 09:46 PM
I appreciate all the help, folks. My first sojourn into this pump area is going to be a big learning experience. Forgive my ignorance but I am studying anything I can get my hands/mouse on. We all have to start someplace.

Thanks again WB for all the great info and assist. You have been a great help on different questions over time. Needless to say, I am very apprehensive about this job. You have made it a lot easier. I believe I have enough wiggle room that I can supply the pump you recommend and the homeowner can do what he wants with his. It will keep me off the hook, so to speak, when my design works as planned based on what I know as to flow and pressure that are available. Been giving me fits trying to make a system work with his pump.

I will still plan on a 2" mainline regardless of pump. I have a lot to learn about pumps and I know that this job is probably not the place to start but the owner is bound and determined that we are the company that is going to install his system. With the competition here being what it is, asking for local help is not an option.

Thanks again for all the help.:waving:

John

Wet_Boots
02-21-2007, 12:35 PM
Pumps can be immensely frustrating. The Hunter technical information file covers a lot you want to learn. Make certain the suction line is absolutely leak-free, and large enough to not have excess friction losses. Suction line friction losses, if they're large enough, will prevent proper operation. That's the "Net Positive Suction Head Required" value you will see on various pump performance curves.

Of course, any output psi numbers you see on a chart will have to be reduced by the elevation you will be pushing the water uphill.