Sprinkler Question

[farmerjo]

Hi,

Have read through most of the archived irrigation threads but cant find my answer.

http://www.superproducts.co.th/English/Sprinkler/nelson/duplex%20a.pdf

I have this sprinkler and what i need to know is,how get the maximum radius(40 metres) out of it.

Will maximum pressure(5 bar) do it alone or will i need maximum flowrate and largest nozzle size as well.

Thanks

[kickstart]

I am no expert,but when out and about I see a irrigation systems ,the 40 meter one ,are ,4 inch pipes, ,and 3inch sprinkler ,power source is either a 6 cylinder truck engine or a pick up engine ,what the flow rate/head of the pump is I do not know .

So I would say yes ,you would need maximum flow rate and a bigger nozzle ,I did notice from the supper products web site that 40 meters is maximum distance for that sprinkler .

Another website ,for 40 meters @ 5 bar .they speck was 20 mm nozzle ,and a pump capacity of 617 litres/minute .

My system ,we used 3 inch pipes ,and a 2 inch sprinkler, on maximum flow rate for the pump I could get 25-28 meters.

[farmerjo]

Thanks KS,

Do you use one sprinkler and move it around

Been searching for hours and finally found it

.http://bigsprinkler.com/products/sime-duplex-sprinkler

Gives me a starting point now to do a bucket test for flow and get some fittings for a pressure guage.

[kickstart]

Hi FJ

Our system was like the Thai way ,a main,and the laterals coming off, with "T's" coming off the laterals for the sprinklers ,I just used one and moved it up the laterals ,a right headache getting it right ,trying to get a 40-50% overlap ,also I was not they the whole time and the misses had to move it ,trying to keep the job simple.

We did this on a crop of sweet corn ,used the sprinklers to get the crop going ,then used ,flood irrigation system ,I do not like flood irrigation ,uses a lot more water ,hit and miss not an even converge, but an easy way to irrigate a crop .

[farmerjo]

Hi FJ

Our system was like the Thai way ,a main,and the laterals coming off, with "T's" coming off the laterals for the sprinklers ,I just used one and moved it up the laterals ,a right headache getting it right ,trying to get a 40-50% overlap ,also I was not they the whole time and the misses had to move it ,trying to keep the job simple.

We did this on a crop of sweet corn ,used the sprinklers to get the crop going ,then used ,flood irrigation system ,I do not like flood irrigation ,uses a lot more water ,hit and miss not an even converge, but an easy way to irrigate a crop .

Hi KS,

Have been making a plan for a sprinkler system the last few days.At the end of it,for now will spend the money to level the field correctly when have the opportunity.A decent system costs a lot of money compared to flood irrigation.

I,like you am not a fan of flooding as you say to get an even distrubution of water with humps and hollows in the field as the hollows if not careful seed will burst or become waterlogged.and stunt growth.

Even with the sprinkler throwing a 40 metre radius i would still need about 22 stations to get an even spread on 15 rai.

Can get 23 metres out of the sprinkler radius for now with excisting pump and pipe so will keep it as back up for the near future and continue to flood for the time being.

[BSJ]

As a test I set up a similar sprinkler head and tested it when we watered the corn first time. I used a little 1.5" 2 stroke pump with the 1.5" pipe over a 40 metre length to the sprinker head.

Running at 3/4 throttle it sprayed the water about 20M but it didn't spray well in the first 5 or 6 metres so we flooded the area a few days later.

I'd say it would need 6 or 7 hp per head minimum for 40M spray...and not use push fit blue pipe! Unless you glue screw fittings on the pipe.

Good luck!

[farmerjo]

As a test I set up a similar sprinkler head and tested it when we watered the corn first time. I used a little 1.5" 2 stroke pump with the 1.5" pipe over a 40 metre length to the sprinker head.

Running at 3/4 throttle it sprayed the water about 20M but it didn't spray well in the first 5 or 6 metres so we flooded the area a few days later.

I'd say it would need 6 or 7 hp per head minimum for 40M spray...and not use push fit blue pipe! Unless you glue screw fittings on the pipe.

Good luck!

Hi BSJ,

Yes,i'm not a fan of pvc pipe either,That sprinkler i have has a diffuser screw to adjust the pattern if flow or pressure is not quite correct to even it up.Still not enough to convince me to go down that path.

The more we talk about sprinklers may help the rain to continue.

[BSJ]

Back in Australia when dad still had the farm he used cam lock aluminium pipe which was a great way to do it. The cam locks can withstand a lot of pressure and undo easy as.

Would be interesting to see what they can do now with cam locks on plastic pipe.

[farmerjo]

To add a bit more info for field layout.

http://www.nelsonirrigation.com/media/resources/BG_SOLID_SET.pdf

To find the right size pump and power unit is the difficult task.

Any recommendations.

[BSJ]

Crikey mate, with 3 or 4 of those sprinklers going you need a serious diesel engine to push the water through the pipes. The 100 Series is a ball tearer!

"75 Series Big Gun with 0.6” nozzle @ 60 psi (4 bar) on a grid of 120’ x 150’ (36m x 45m). Flow per unit is 77 gpm (17.5 m3/hr), application rate is 0.4 “/hr (10 mm/hr). Lateral pipe diameter is 3” (80mm) 100 Series Big Gun with 0.8” nozzle @ 70 psi (5 bar) on a grid of 160’ x 180’ (48m x 54m). Flow per unit is 155 gpm (35 m3/hr), application rate is 0.5 “/hr (13 mm/hr). Lateral pipe diameter is 4” (100mm). "

Why don't you contact the company and get them to send you some statistics?

[farmerjo]

Crikey mate, with 3 or 4 of those sprinklers going you need a serious diesel engine to push the water through the pipes. The 100 Series is a ball tearer!

"75 Series Big Gun with 0.6” nozzle @ 60 psi (4 bar) on a grid of 120’ x 150’ (36m x 45m). Flow per unit is 77 gpm (17.5 m3/hr), application rate is 0.4 “/hr (10 mm/hr). Lateral pipe diameter is 3” (80mm) 100 Series Big Gun with 0.8” nozzle @ 70 psi (5 bar) on a grid of 160’ x 180’ (48m x 54m). Flow per unit is 155 gpm (35 m3/hr), application rate is 0.5 “/hr (13 mm/hr). Lateral pipe diameter is 4” (100mm). "

Why don't you contact the company and get them to send you some statistics?

Hi BSJ,

If it ever happened i would use their layout and purchase another sprinkler the same as i have and would be the manual system of only one

running at a time and the other ready to go.

I am currently waiting to see what happens with my local electricity,were in line to get a transformer outside the gate when the new power

goes past.

Whether 3 phase will be available i'm not sure as i don't know how that side works but that will have a big bearing on which way i precede.

Without measuring i would think my total head is not more than 20 metres.(lowest water point to highest piece of land)

[farmerjo]

Has anyone seen these direct drive motor to pump couplings(red) in thailand.

http://www.wheeltractor.com/products/offer/water-pump-with-engine.html

Thanks

[kickstart]

Has anyone seen these direct drive motor to pump couplings(red) in thailand.

http://www.wheeltractor.com/products/offer/water-pump-with-engine.html

Thanks

Hi FJ.

Some thing I have not seen in Thailand ,but how about 2 male pto shafts,,1 on the pump,1 on the engine .mount it all on a frame, and use a female pto coupling for the drive .

A good idea direct drive ,no belts and pulleys to worry about ,but with out belts and pulleys ,you can not do any thing about the gearing of the pump ,got visions of the engine running flat out ,pump working at half rev's .

[farmerjo]

Has anyone seen these direct drive motor to pump couplings(red) in thailand.

http://www.wheeltractor.com/products/offer/water-pump-with-engine.html

Thanks

Hi FJ.

Some thing I have not seen in Thailand ,but how about 2 male pto shafts,,1 on the pump,1 on the engine .mount it all on a frame, and use a female pto coupling for the drive .

A good idea direct drive ,no belts and pulleys to worry about ,but with out belts and pulleys ,you can not do any thing about the gearing of the pump ,got visions of the engine running flat out ,pump working at half rev's .

Hi KS,

That's the senario i'm getting with v-belts.

With a Yanmar 14 hp engine,you need it to run at 2400 rpm(flat out)to get 12 hp.

But i cant get near that with the pump because of slippage.and don't want to cause bearing damage from over tightening the belts.

The pumps mid working range is 54m3/hr at 56 metre head at 2400 rpm is 12 hp required.

I think direct drive would get me pretty close.

It wouldn't take much to set up the PTO shaft connection,would just have to moniter it carefully.

I have been doing a bit of a feesability on sprinklers for 90 rai.The price roughly to set up a fixed piping system,4" main line and 3" laterals and

associated fittings and labour would cost 285,000 baht.That is working on running one sprinkler at a time(moving sprinkler head) and no cost of the actual right size pump and power supply.(if what i have alreadyis unsuitable)

Where it gets tight is i have roughly a water holding capacity on the farm of 11,250,000 litres for 7-8 months of the year.

55 sprinklers doing 2 hours each(8 hour day) would apply 25mm of water at each station every 14 days,so 50mm or 2" of water for the month.

That gives me just over 2 months water supply.now if i ran the bore pump to top up the main dam when i start irrigating it would take 2 months

constant running to give me an extra month of water supply.

The million dollar question is,by keeping the soil living 12 months a year,will the fastracking of soil health help offset the running costs.(yet to get to that part)