# Need Advice On Main Line



## xSparkleZ (9 mo ago)

I've spent countless hours on this forum and Irrigation Tutorials website; however, I wanted to have someone proofread my draft for the Main Line POC.

I have a 3/4" Water Meter feeding into 3\4" Copper. 
I'm having a plumber add a T right after my Water Meter to add a drain at the bottom and then increase the other side to a 1" Copper run that will go through my exterior wall. 
Before it enters the wall, I plan to have the 1" Copper transition to 1.25" Pex and then to 1" copper as it would be easier to wrap around several floor joists and the increased Pex is to ensure the inner diameter is somewhat similar along the run.

Once the Copper exits the house, add a T facing down, and the horizontal will have a hose bib.
On the bottom of the T, it will have a ball valve, the RP Backflow Preventor, Screen Filter, transition to Sch 80 PVC, and then enter the ground where my Valve Manifold will be located. 
Everything past the bottom of the T will be piped under the Cantilever. 
Picture and scribbles have been attached.

I live in a northern climate susceptible to freezing conditions, so I would like your insights on the following:

_Will the RP Backflow Preventor on the exterior of the house cause any issues in winter?

Can I transition the Sch 80 PVC right after the Ball Valve on the bottom T?
I plan to paint over the PVC to give it UV protection.

Considering I have the POC exiting the house like 6 ft from the ground beside my vent, alot of garden hose on the hose bib which might be heavy, Backflow Preventor and other fittings and pupe that are heavy, would my 1" Copper through the wall be able to hold that much weight considering I have Pex to Copper transition inside the home right before it goes through the wall?

Should I use Sch 80 PVC after the Pex inside the house and have it just go through the wall instead of the Copper I have planned?

Anything else you see that is incorrect or I should ammend to make my life easier in the future?

Consdiring my Water Meter is 3/4" and even though I am transitioning the size to 1" would that cause any concerns for water pressure or should I go larger to 1.25" after the water meter to reeuce the number of valves I'll require?_

I have included pictures of my setup for a visual.

Thank you in advance for your help. 
This is a difficult hobby to learn, but I am grateful for all your support.


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## g-man (Jun 15, 2017)

On the side of the house (assuming it is conditioned space), you want to do the T from the main, then add the ball valve. After the ball valve you want a way to bleed the water out of the pipe that it is outside the house. This is important to avoid water freezing in the winter and breaking your pipes.

After the bleed point, you can go outside and to the backflow and any other connection. You want to ensure all of the pipes are secure to the structure with pipe hangers. You should not trust the copper pipe to sustain the weight. Think of the scenario of someone pulling on the garden hose and ripping your system apart with water going everywhere.

Pipe diameter is a function of water pressure and flow to the pipe. Bigger is better or marginally better, but never a negative outside of being more expensive.


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## xSparkleZ (9 mo ago)

Thank you for your input!
It gives me a sense of relief that it's on the right track.

I made some adjustments and will be installing a double check valve backflow preventor assembly instead as I'll be able to have it located indoors and below ground in the basement. 
The Watts 007 1-inch model should be arriving shortly.

As it stands now, we will add the T after the water meter, transition from 3\4" to 1" into a ball valve, then the screen filter, then the backflow preventor, then another ball valve, then another hose bib to drain the riser that will exit the home, and then exit the home.

On the exterior, it will enter a T, one way to a hose bib which I'll use as my connection to perform blow out, the other end will wrap below the Cantilever and head down to the valve manifolds. Eventually, it will transition to PVC 1" once it goes under the Cantilever to protect it from the elements.

_Should the mesh filter go before or after the backfow preventor?

Any suggestions or corrections?
_
By the way, I prepared the area below the Cantilever the other day to prepare for the valve manifolds and put down some timber edging with pressure treated posts. I am just waiting for my order of black mulch to lay above the landscape fabric.


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