# Irrigation Rebuild - Manifolds lower than distribution pipe



## chules (May 11, 2020)

I'm trying to correct some problems with my irrigation. I had the system installed about 15 years ago and it never really worked. The irrigation company never checked my water pressure, tried to install a booster pump, and only went down 4 inches or so with the main valves and vale boxes. Even worse, there's exposed 3/4 poly pipe runs where the pipe was just buried an inch or so underground. Very sloppy so I decided to rebuild it.

I've replaced my water meter, installed an RPZ backflow preventer, and changed from 3/4 inch poly to 1-inch poly. I replaced all my valve boxes and manifolds with Hunter PGV Vales and Hunter drip valves. I went down 18 inches with the main pipe and manifolds below the frost line and added ports to connect my compressor to winterize.

The issue I have now is my main manifolds at 18 inches are lower than the distribution pipe. Some areas of distribution I'm replacing and will trench but other runs I'm wondering if I could come out of the vale with a few inches of poly and then an elbow to tie into the distribution pipe. I'd tie into the distribution pipe with a 10-12 inch vertical rise. Has anyone run into this situation where you need to go vertical out of the manifolds to connect to distribution piping. I'm not sure if this would cause irrigation issues? With my home's plumbing the water rises from the crawl space to the 3rd floor without issues.

Any advice greatly appreciated. Thx


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## Utk03analyst (Jun 8, 2019)

For my build I just sloped up and down versus using more fittings which I would say is an advantage of poly vs. pvc but I'm no expert but more fittings would be more joins and more possible leaks in the future.

My valve boxes are not that deep the top of my solenoids on my 1 inch pgv's are about 1 inch below grade. I'm also in middle TN it does get cold but nowhere near the Midwest or Northeast. I plan on blowing everything out, but my main line is 18 inches deep but I have a drain and a blowout point for winter.


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