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Plumbing size to valves and sprinklers?

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bassadict69

New Member

Posts: 11

Location: Benton, La

1

Sunday, April 27th 2014, 9:10am

Plumbing size to valves and sprinklers?

I am slowly piecing together an irrigation system. I have a Red Lion 2hp centrifugal pump pumping water from the lake, it has a 2" suction and a 1 1/2" discharge. I currently have the discharge simply ran off the pump to a garden hose spigot on my dock and teed off to a fish cleaning table.

I am now ready to extend the discharge up to my yard to a valve setup. Should I stay with 1 1/2" to the valves then reduce to 1" throughout the yard? Or stay with 1 1/2" throughout the yard?

Central Irrigation

Supreme Member

Posts: 364

Location: Central Minnesota

2

Sunday, April 27th 2014, 12:30pm

What will be the flow rate of the zones, and how long of a run will the mainline be to the farthest zone valve?

bassadict69

New Member

Posts: 11

Location: Benton, La

3

Sunday, April 27th 2014, 4:10pm

I will have to measure the longest run to be exact, but close to 150ft. As for the flow rate of the zones, I have no clue...How would I find that out since my zones have not been set up yet. Right now, it is looking like 4 zones with 4-5 heads per zone.

Wet_Boots

Supreme Member

Posts: 4,102

Location: Metro NYC

4

Sunday, April 27th 2014, 7:47pm

Depending on elevations of the property relative to the pond, it might be possible to design a system that can water all of a lawn simultaneously, if you take advantage of the performance curve of the centrifugal pump, which should be able to pump over 60 gpm at a usable pressure. That is easily enough for more than 20 rotor heads.

If you could manage an all-at-once system, the savings is mostly time and electricity, since the very high flows require the plumbing be up-sized to match. Also, the output pressures at these peak-efficiency flows are lower than you might want for many common rotor heads. That noted, this sort of pondwater system is tailor-made for using Maxipaw impact heads (the pro version of the cheapie plastic impact heads sometimes found in home centers) which can handle crummy pondwater better than any other head you can buy.

Cdairrtech

Unregistered

5

Sunday, April 27th 2014, 8:41pm

The info you will need to know to make this work are:
- what is the elevation difference between the pump and where the heads and valves are?
- what will the water pressure and volume be at that elevation? You will need to find the pump curve of that pump to know. Otherwise, you will need to run the line up the hill, stick a tee on the end with a manual valve on one side and a pressure gauge on the other. Flip the pump on, start cracking the valve and open till the pressure drops to the target min pressure. That will be your dynamic or working pressure when the system is on. You can then time how long it takes to fill a marked container like a five gallon bucket to know your GPM at that desired pressure, but design your system to use a little less GPM than what you find.
- what is the size of the area you want to water? Once you know how big the area is you want to water, you will be able to select the proper sprinklers.
- what size pipe? This ultimately is determined by your pump output. 1 1/2" pipe from your pump to your valves sounds like a good plan but from there, unless you have a gigantic yard, it makes sense to stick with 1" valves and pipe. The cost would get driven way up to move up to 1 1/2" , as well as difficulty of installation. Plus, if your pump only puts out 15 GPM, there is no reason for 1 1/2". This will also determine how many sprinklers and what GPM you can use on each zone.
- How many sprinklers and what nozzles will they use? Once you know the area, how many sprinklers and what nozzles, you can then start splitting things up to fit how many GPM you have. This will dictate the minimum valves you will need. You can split it up further for more control over potential problem areas with more valves.
Going online to some of the manufacturer websites will let you look at all the specs of their heads.

Hope this helps line it out a little.

bassadict69

New Member

Posts: 11

Location: Benton, La

6

Monday, April 28th 2014, 1:58pm

Quoted from "Cdairrtech"

The info you will need to know to make this work are:
- what is the elevation difference between the pump and where the heads and valves are? 5-6 ft at the highest which is also the farthest point

- what will the water pressure and volume be at that elevation? You will need to find the pump curve of that pump to know. Otherwise, you will need to run the line up the hill, stick a tee on the end with a manual valve on one side and a pressure gauge on the other. Flip the pump on, start cracking the valve and open till the pressure drops to the target min pressure. That will be your dynamic or working pressure when the system is on. You can then time how long it takes to fill a marked container like a five gallon bucket to know your GPM at that desired pressure, but design your system to use a little less GPM than what you find. Here is the link to the pump info... http://www.redlionproducts.com/lawn-irrigation/centrifugal-self-priming-sprinkler-pumps/

- what is the size of the area you want to water? Once you know how big the area is you want to water, you will be able to select the proper sprinklers. about 150' x 150'

- what size pipe? This ultimately is determined by your pump output. 1 1/2" pipe from your pump to your valves sounds like a good plan but from there, unless you have a gigantic yard, it makes sense to stick with 1" valves and pipe. The cost would get driven way up to move up to 1 1/2" , as well as difficulty of installation. Plus, if your pump only puts out 15 GPM, there is no reason for 1 1/2". This will also determine how many sprinklers and what GPM you can use on each zone. Exactly what I am trying to figure out...

- How many sprinklers and what nozzles will they use? Once you know the area, how many sprinklers and what nozzles, you can then start splitting things up to fit how many GPM you have. This will dictate the minimum valves you will need. You can split it up further for more control over potential problem areas with more valves.
Going online to some of the manufacturer websites will let you look at all the specs of their heads. About 30 sprinklers, not sure which ones.

Hope this helps line it out a little.

Wet_Boots

Supreme Member

Posts: 4,102

Location: Metro NYC

7

Tuesday, April 29th 2014, 12:48pm

Come back with your system design in a diagram, and more specific advice will be forthcoming. Some of the manufacturers have design services for homeowners.

How things will divide up, if at all, will depend on the dimensions of the watered areas, and the sprinkler heads that will fit them.

By the way, "Lawn Sprinkler Pump" is in general, a big fat lie of a product name. These pumps are not well suited to meet most sprinkler system requirements. Not enough pressure. The "Jet Pump" types are much better fits. Most folks will use a pump like yours at close to its highest output pressure, and never will they know that a jet pump of less than a horsepower would push the same water for a fraction of the operating cost.

bassadict69

New Member

Posts: 11

Location: Benton, La

8

Tuesday, April 29th 2014, 1:14pm

I will get a design from someone like Rainbird, then check back.

As for my pump, I spent lots of time asking neighbors, riding around in my boat looking at pumps on peoples docks, etc. No one out here is using anything special...lots of the home depot and lowes pumps. My next door neighbor has a lot more to water than I and his HD pump is kicking ass on a daily basis! How long they last remains to be seen.

Thanks everyone for the help so far...I know best scenario would be to hire someone to install this system, but 5-7 grand is a little out of my reach.

Central Irrigation

Supreme Member

Posts: 364

Location: Central Minnesota

9

Tuesday, April 29th 2014, 2:49pm

Have you got any bids yet? $5k for a system that size with a pump and electrical already installed is on the highside. Get some bids, you might be surprised. At least for my neck of the woods.

Wet_Boots

Supreme Member

Posts: 4,102

Location: Metro NYC

10

Wednesday, April 30th 2014, 3:31pm

Operating cost is almost never figured into a design pumping lawn sprinkler water from a pond, so there is no doubt that the vast majority of systems near to you will employ a single-stage centrifugal pump that will use at least twice the power compared to what a smaller jet pump would consume for the same amount of pumping. Those pumps happen to be cheaper than jet pumps, and that's why you see them.

The folks that do spend an extra hundred or so for a good jet pump, like the Goulds J10S or J7S, get higher water pressure and lower electric bills. That higher water pressure is absolutely key to being able to get the best performance from sprinkler heads that require 40 psi or more good water distribution. That pump you mentioned is all but gasping and wheezing by the time gets to 40 psi, and that leaves it still needing more to account for pressure losses in pipes and valves and fittings.

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