# Upsizing copper supply to irrigation



## mooch91 (May 5, 2019)

All,

I have a 1" copper line coming from my well pump system that reduces to a 3/4" line to feed the main solenoid valve (Hunter jar-top valve) for my irrigation. The main solenoid valve is 1" as are all of the main poly and lateral poly lines.

I'm interested in upsizing the supply line from the well pump to the main valve to a full 1". I'd like to ensure maximum flow and pressure to the heads from the well pump.

Two questions:

My system was installed with only a check valve in this line, which I know would likely not meet any minimum expectations for backflow prevention. The elevation change across my yard is significant, with the point of connection being about halfway across the change in grade; as such, a standard BFP would not be appropriate (the highest elevated head is at least 10' above the point of connection). Please help me select an appropriate outdoor backflow device that can be used for this application.
Looking for tips for mating the copper line to the main solenoid valve. Any advice for making the solder connections so I don't melt the valve/valve body? Since the valve is underground, I'm not seeing a way to avoid soldering at least within 6" of the plastic valve. I have plenty of experience soldering, but only on copper-to-copper systems, never where copper is near plastic.

Thanks!


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## g-man (Jun 15, 2017)

1) since you are in a well, you don't need a backflow preventer as long as you are hooking up before any in house filter system. (I'm assuming you use the well pump for the house too). If you want one, then the best option will be RPZ.

2) I would just order a new valve with threaded ends.


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## mooch91 (May 5, 2019)

g-man said:


> 1) since you are in a well, you don't need a backflow preventer as long as you are hooking up before any in house filter system. (I'm assuming you use the well pump for the house too). If you want one, then the best option will be RPZ.


I stand corrected, I currently have a _dual_ check valve installed to prevent backflow.

Apparently, a _double_ check valve is a better choice piece of equipment than the dual check valve. Ideal would be the RPZ, but since it has an air gap between the check valves, it needs a place to drain (and with quite high volume and pressure should it ever get stuck).

I'll probably upgrade to the double check valve when I change the pipe size.


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## mooch91 (May 5, 2019)

g-man said:


> 2) I would just order a new valve with threaded ends.


The existing valve does have a female thread, so I will screw in a male adapter (copper) sweat to a 6" stub of pipe which would be sweat to an elbow. At this point, I need to begin sweating the copper in place since the pipe comes up out of the ground about 8" before it goes through the basement wall of the house. My concern is with sweating it in place - since it would be threaded in to the plastic valve at this point, I don't want it to get so hot as to melt the valve.


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## g-man (Jun 15, 2017)

I see. Maybe add a union then.


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