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Water Supply Connection for House and Irrigation

I'm installing an irrigation system and I need to replace the tee that goes into my house to use one side for my sprinklers (instead of an existing hose bib). The existing installation is 3/4" copper pipe (from the meter) to a compression fitting, then the main shutoff 1", then a galvanized union 1", then the tee into the house and hose bib. After the tee, I'll have a pressure vacuum breaker, then SCH 40 PVC to the irrigation valves.

When I replace the tee, must I use galvanized again? I would prefer pvc with threaded connections (SCH 80?), but this is above ground. If I wrap it in pipe insulation and electrical tape, will it be to code? This is PVC after the main house shutoff just outside the structure.

Re: Water Supply Connection for House and Irrigation

We can't tell you if it is to code. Don't know where you live. It isn't code in my fair city, but that don't make much difference to you.

Why the aversion to copper?

I'd add an additional shut off valve before the entire irrigation system, but I'm ocd that way.

Re: Water Supply Connection for House and Irrigation

Well, just trying to think out how this should be done. So if I install copper, I would need to remove the existing shutoff and connect directly to the soft copper pipe with a new compression fitting? (installing a new shutoff before the house connection)
Then I would need to connect to the existing galvanized pipe...how would that be done?
I'm probably more ignorant of copper than averse to it, but I am willing to learn.

Re: Water Supply Connection for House and Irrigation

Rule #1: Copper and galvanized can't mix. Copper and brass mix. Copper and Sch 40 pvc mix.

In Southern california, this is how you do it:
- from the meter to the house: 3/4" or 1" copper (in most average homes).
- pipe goes up and there's a main shut off valve.
- past the valve there's a T.
- one side of the T gets a relief valve.
- other side of the T gets a pressure regulator (reducer), with a union. The regulator is made out of brass.
- past the regulator there's a second T.
- one side goes into the house.
- the other side gets a hose bib.
All fittings are copper. Solder all fittings and adaptors. Use only lead free solder. Don't use compression fittings.

Now you need to add an irrigation system. This is how you do it:
- pipe from the meter rises up. At about 6" to 9" put a T. one side continues to the main shut off valve and so on to the house.
- the other side of the T will get a second shut off valve, for the irrigation system. If you street water pressure is high, I would add a second pressure regulator.
- past the regulator you can start your sch 40 pvc pipes.

This way, the house water supply and the irrigation water supply are split, and each one has a shut off valve. So you can go on vacation, shut the water to the house, but let the sprinklers run as normal.

Good luck.

Re: Water Supply Connection for House and Irrigation

So I would sweat the 3/4" soft copper into a valve (or stub piece first, then valve) and then into a tee...how do I make the connection to the existing galvanized house piping?

Re: Water Supply Connection for House and Irrigation

If you have galvanized pipes inside you home, maybe this would be a good time to repipe with copper.

If you can't do a repipe right now, place a brass fitting (a 2" nipple or a coupling) or a dielectric union between the existing pipes inside and the new copper pipe outside.

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