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Wednesday, May 29th 2019, 3:58am

Range issue with PGP Ultra and MPR-35 nozzle

Hello,

I am currently building my lawn irrigation for about 5000 square feet. The sprinklers are planned as three zones, each with about 10GPM flow. At 10GPM, the pump delivers 58 psi (measured), next on the main line is a 100-mesh y-filter. Pressure loss from the filter should be about 3 psi. I decided to design with PGP Ultra rotors and MPR-nozzles, mostly MPR-30, some MPR-35.

One zone is giving me range headaches. It's the simplest one, with only 2 PGP Ultra and big MPR-35 nozzles. Overall it's 90 feet long, with sprinkler 1 at 60 feet and sprinkler 2 at 90 feet.

Sprinkler 1 has an MPR-35 nozzle for full circle, and is located in the middle of the pipe. Sprinkler 2 has a nozzle for a half circle and is located at the end.

The pipe is PE-HD with an inner diameter of 1", the sprinklers are mounted with a clamp saddle and a 3/4" swing joint, 12" long.

The sprinkler in the middle (full circle) seems to throw way shorter than the expected 35 feet. I guess it's about 24 feet. The half-circle sprinkler at the end of the pipe works much better.

I don't think the installation is to weak - the 1" PE pipe is adequate for 10 GPM, and imho, a 3/4" saddle clamp and a 3/4" swing joint are the right way to install a PGP Ultra.

Can you point me at what to check? I looked at the sprinkler's filter which is clean.

There is one thing that surprises me about the MPR-nozzles, and it might be related: Their spray arc is extremely shallow. The tan MPR-35 360° nozzle has a very shallow angle, and it seems to me like this is bad for the range. I think about changing to a blue "8"-nozzle, as the throughput is similar, and it throws way higher. But I suppose that mixing MPR- and regular nozzles will not give me an even coverage?

I am at a point where I even think about changing all nozzles to regular blue standard nozzles...

Best regards,

Detlev

This post has been edited 8 times, last edit by "top_gun_de" (May 29th 2019, 7:13am)


2

Thursday, May 30th 2019, 12:08pm

Ok, after trying blue 6 to replace a MPR35 full circle with good success, i replaced all nozzles with blue ones. I think these are matching replacements:

MPR30 quarter: Blue 1.5
MPR30 third: Blue 2.0
MPr30 half: Blue 3.0
MPR30 full: Blue 6.0

The range is a bit better, so I could even replace MPR35 with the same rule-set.

My father's day trip was entirely water: Replacing all existing nozzles with their blue counterparts, and checking coverage all over the lawn.

I am now a happy camper.

Concerning precipitation rate: While the flow is not exactly the same as the green and tan nozzles, I made a calculation based on 45 psi and the aggregated flow is almost exactly the same as I had with the green nozzles.

Seems like buying the MPR nozzles was a waste of money. But you gain experience whenever a plan hits reality. I am now a little wiser at the cost of 10 bucks :) Googling around for experience with these nozzles gave me nothing but shops who sell the stuff. Based on what I saw, the commendations are a joke. They might be fine in a concrete hall, but a lawn with just a bit of elevation (around 8" over 30 feet) ruins the calculation.

This post has been edited 1 times, last edit by "top_gun_de" (May 30th 2019, 12:16pm)


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