# Flow Meter and Master Valve



## cem367 (Apr 19, 2020)

Hello,
I have some questions about location and set up of a hunter flow meter and an addition of a master valve. I recently expanded my irrigation system to 6 zones from the previous home owners original 3 zones. They never installed a master valve and just as a precaution I wanted to add one. Now that I've got my hands dirty adding 3 zones I feel a bit more confident in what I'm doing.

Master valve - Can I install this in the basement after the back flow and shut off valve as it's pretty close to my base station. Rather than digging up more space near the outside box I wanted to make sure this was fine. Also, they ran 3/4inch Pex from the backflow preventer to the outside line 3/4 copper. (main irrigation is all 1 inch poly). I'm assuming I would use a 3/4 valve here and tie into the pex and not use a larger 1 inch and down size the fittings?

Flow Meter - Similar questions.. I know this needs to have some pipe before and after the valve with that in mind.. Can I also install this in the basement and attach to the same 3/4 pex pipe? Would I also stick to a 3/4 flow valve and not use a 1 inch valve and down size with fittings?

I figured this method would be easier since I can easily tie both of these into the control box and save some headache doing more digging.

Thanks for any help!


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## Gene (Apr 17, 2020)

Considering that you are installing master valve and flow meter downstream from the back flow presenter, the location (inside/outside) should not matter. Just keep in mind that valves (master or otherwise) may leak during servicing so install it with enough room to be able to place a pan or a bucket so you are ready down the road.

It is a good idea to keep everything the same 3/4 size. Resizing (3/4 to 1" and back) creates turbulence which is definitely not good for the meter's accuracy. As far as valve performance, installing a 1" valve on the 3/4 run would not result in meaningful gains, just be sure to use ball valve that keeps 3/4 path throughout (when looking down the barrel of some metal valves, you will see that the opening is actually smaller to minimize ball size).

Being from Florida, I'm not an expert on basements, there may be good reasons to keep these parts outside, but if you include some sort of wet/leak sensor to alert you in case something leaks, keeping these parts protected during winter will allow them to serve you longer, even if they would be properly winterized if installed outdoors.


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## jht3 (Jul 27, 2018)

Mine was installed with a check valve and 3/4" master valve in the basement, near the main shut off.

I have ball valves bookending the two valves for maintenance and winterization. All copper pipe. Conversion to pvc happens outside.

My zone valves are 1"


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