Water Supply Connection for House and Irrigation


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Old 06-02-11, 04:16 PM
J
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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.
 
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Old 06-02-11, 08:33 PM
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Let's say I need to change my main house shutoff from a gate valve to a ball valve. I have 3/4" soft copper coming in and 1" galvanized pipe inside. What is the best way to make this connection?
 
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Old 06-02-11, 10:02 PM
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Theres alot of considerations here. For what its worth I will just mention some things before you start. Save you some trouble down the road.

1. I would keep your main all metallic pipe. Then off the tee put a valve then convert to PVC. Use brass not copper.

2. What is your house pressure? How manu gallons per minute do you have? This will determain what size to pipe your sprinkler. Even though 3/4 main, you may need a 1' sprinkler main line.

3. If you have high pressure you may need to reduce it, or sprinklers will mist. Rotors work well at 50 psi, but the sprays mist above 40 psi. Of course you need to account for friction loss in the piping.

4. Is the vacuum breaker outdoors? They squirt water from time to time. And if it gets hung up, it would not be a pretty site if it was indoors.

5. The best way to make the connection IMO is to find a threaded portion on the galv. pipe and convert to brass. From galv. pipe, brass adapter, brass nipple, brass tee, brass threaded ball valve, brass nipple, brass adapter, copper main.



Hope this helps.

Mike NJ
 
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Old 06-02-11, 10:16 PM
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Thanks a bunch for this info. A brass tee is sounding like the best option at this time.

My pressure ranges through the day from about 45psi to about 55psi. It's about 10.5gpm. I'm planning for a 1" main line and 1" to my biggest zone and 3/4" to other zones.

PVB is outdoors.

Is there any galvanic corrosion problem with going from copper to dielectric union to galvanized to brass to galvanized again?
 
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Old 06-02-11, 10:26 PM
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You can use dielectric unions. I dont like them. The rubber can wear out, and some people melt the pastic sleave while sweating them. Then they just become a galvonic mess...is that a word?
Mike NJ
 
 

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