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The last 10 posts

Monday, June 23rd 2008, 12:27pm

by mrfixit

MP Rotators

I'd like to make one suggetion if you're going with the MP Rotator. I'd buy just enough for one zone at first. Like hkd said, these aren't cheap. I've had problems with these trying to solve issues similar to yours. The MP Rotator nozzel itself needs a certain amount of pressure to pop up before it will function. If they don't pop up then they'll work worse than what you have now.

Monday, June 23rd 2008, 8:39am

by Wet_Boots

With a zone of 16 half-circle sprays, you can always close down the nozzle adjusting screws, one head at a time. At some point, you should get good performance from the working sprays, and you can use that for establishing a flow rate you can work with.

By the way, there is a chance that there is a partially closed shutoff valve in the meter pit, or elsewhere, and that should be eliminated as a possibility.

Monday, June 23rd 2008, 7:49am

by HooKooDooKu

At this point, the blame game (no mater where it leads) isn't going to get anything fixed in this situation.

While not cheap, the quickest and easiest solution for your popup zones could be Dan's suggestion of the MP Rotators. They are basically replacement nozzles (so you don't have to dig up the pop-ups) that convert a spray to a rotator. Once set for a 12' half circle spray pattern, each will use only about 0.5-0.6 gpm. For a 16 head zone, that can be as little as 8gpm. Now they are not cheap (somewhere in the neiborhood of $7 each). So if you've got something like 50 heads, that's going to be about a $400 upgrade. So I would suggest that you get enough MP Rotators to replace all the nozzles in the zone with the fewest head. That will be less than a $100 test and could solve your problems. If so, then suddenly the ease if this fix will be more than worth the $$$.

Sunday, June 22nd 2008, 10:58pm

by hi.todd

After you do a flow test. See what you have to work with. Usually,the MP rotor that used to be walla walla sprinkler company and sold them to Hunter, can fix flow problems because they can run on 30 PSI and usually have a lower GPM than spray heads and rotors. You may want to convert the whole system. Open a hose bib at the house, close the meter and then open it. Sometimes meters take more than 360 degrees to open up all the way. You opened the hose bib so that you can watch and listen as you open and close your meter to understand when it is fully open. Your meter can be in need of repair or your line can be kinked. You will need to verify what it is you are working with flow wise.

Good Luck.

Dan :thumbsup:

Sunday, June 22nd 2008, 9:39pm

by atkinson4738 (Guest)

I think that is the exact point mrfixit. I have installed about five systems, but obviously I don't know the best way to design so I paid the professionals that claim they design them very well. Don't get me wrong though, I love the guys at the plumbing shop they are always extremely helpful and their prices are great, so the "blame" is not really that, it was just a statement of confusion on my part as to why they would have designed it this way.

Aside from this though is too many heads on a line the issue for sure? I was wondering if the main line may be kinked somewhere. I checked the pressure at the manifold and it is the same as it is at the meter (yes the meter is 1 inch). After I did this I kind of realized that really didn't tell me anything because even if the line is kinked it can still build up pressure, but once a valve opens having the pressure maintain would be the issue, correct?

Is there any troubleshooting steps to figure out if my main line may be kinked, or am I going to have to add valves and split the lines? Wetboots - you mention I should be able to handle 15 gpm at 50 psi, do you have any good resources on how I calculate the gpm and how it coorelates to psi?

Sunday, June 22nd 2008, 7:45pm

by mrfixit


So we basically agree. The design shouldn't have been made based on water pressure alone. Here in California, plumbers aren't allowed by law to design a sprinkler system. Landscape contractors aren't even allowed to draw up plans for the yards they install. You need a landscape architect license which is a 4 year degree.

Sunday, June 22nd 2008, 4:44pm

by Wet_Boots

If you aren't paying someone to do actual flow testing, or doing it yourself, you are getting a pig in a poke when you have a design done on the basis of a pressure reading alone. Things may work out most of the time, but someone has to be the unlucky exception. Only by measuring flow and pressure together, can you have an accurate picture of the water supply. Working without that accurate picture is a mistake. Assign the blame wherever you wish, but it was still a mistake. Since a one inch water meter (is it a one-inch meter?) can handle a 50 gpm flow, you'd think you could manage 15 gpm, but that isn't always going to be the case.

Sunday, June 22nd 2008, 3:11pm

by mrfixit


In order to design a system and how many heads to use you need to know the water pressure and the flow rate, gpm. Also pressure lose due to many variables. You can get 50 pds of pressure thru a pin hole. You did say you had 1 inch line though. So "they" did screw up by designing a system without all the information needed. I might be wrong but it sounds like Boots is insuating it's your fault. I say you trusted and paid a professional based on reputation to know what he's doing. I don't do installations anymore. I haven't installed a system for 13 years. I'm strictly repairs. I can tell you I've worked on many many systems with 50 pds and not one of them could run 16 twelve foot half spray heads let alone 40 pds the system was supposedly designed for.

Sunday, June 22nd 2008, 10:10am

by atkinson4738 (Guest)

What do you mean by water supply? I did supply them with my psi (50) and they designed it around 40 psi, so I don't understand what you mean by "verifying my water supply".

Sunday, June 22nd 2008, 8:57am

by Wet_Boots

  • "They" didn't screw up. Installing a system without first verifying the water supply is the screw-up.