# Do I need pressure reducing spray bodies with check valves for MP Rotators?



## Glen_Cove_5511 (Jun 13, 2020)

I have a separate pressure reducer for my supply to the irrigation system I will be installing next month. Right now I'm in the process of picking all of my parts for the install. If I can control the pressure of the supply line, is there any need for me to pay the extra expense for pressure reducing spray bodies with check valves? I will be using a combination of MP 3000s and MP 3500s. Thanks!


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## Ware (Jan 28, 2017)

Using the PRS40 spray bodies helps ensure all of your MP Rotator nozzles are operating exactly at the 40 PSI design pressure.

You can regulate pressure upstream only, but your actual pressure at each nozzle will vary more because there will be different pressure losses on the path to each head due to different lengths of pipe, number/type of fittings, etc.


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## Glen_Cove_5511 (Jun 13, 2020)

Thanks @Ware... I'll get the PRS40 spray bodies and leave my supply line at full PSI. How about check valves in the body, necessary?


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## Ware (Jan 28, 2017)

Glen_Cove_5511 said:


> Thanks @Ware... I'll get the PRS40 spray bodies and leave my supply line at full PSI. How about check valves in the body, necessary?


I didn't use check valve nozzle bodies on my MP Rotator system, but my whole lawn was pretty flat and I had automatic drains on my laterals.


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## BadDogPSD (Jul 9, 2020)

Without check valves, the water in the pipes will drain out of the lowest heads. Not a big deal, but it does waste some water.


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## Glen_Cove_5511 (Jun 13, 2020)

Thanks for the replies @Ware and @BadDogPSD. I'll go with check valves based on the fact my area goes uphill from the house and the lowest heads would dump a fair amount of water.


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## burntfire (Dec 10, 2020)

@Glen_Cove_5511 If you're on a hill absolutely use the PRS40 bodies. It's a few extra dollars but helps maintain a good system.


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## Monocot Master (Feb 28, 2021)

I like check valves in all of mine, both rotors and the fixed sprays for reasons already mentioned. My elevation changes are minimal, but I still get low head drainage without the checks. Also, the Hunter, and I think the Rainbird as well, fixed spray heads with built in check valve have a heavier retract spring.


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