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jaguavai

New Member

1

Sunday, July 26th 2015, 6:24pm

Low pressure from house to system

First post, hopefully I'm in the right spot. And forgive me please if I don't use the proper lingo, I'll try to explain everything in sufficient detail.

Anyhow, we are installing sprinklers on a newly built home. The builder installed the valve for the sprinklers in the basement, which was fine with me as long as it didn't cause problems. Here's the part where I'm unfamiliar with the lingo:
- the main line coming into the home appears to be 3/4"
- maybe 6" further into the house, it's reduced town to 1/2", 2-3" later they've installed the main valve, another 2-3" later there's a pressure regulator and then onward and upward through there to the PEX manifold thing etc.
- just after the main shut off valve, the builder installed a T junction that leads off to the sprinkler supply line and valve
- just before the 1/2" sprinkler line leaves the basement it's coupled back up to a 3/4" pipe

I've got the first four zones in the yard installed and ready to roll. Zone 1 is a drip zone, it appears to be fine. Zone 2 has ten 1gpm heads installed (no heads on the other zones just yet, but valves and pipes are done). So we fire up zone 2 and I don't even get enough pressure to fully activate the heads. The stems on 2 or 3 of them won't even pop up all the way. Being a noob, I'm assuming this means I'm getting less than 10 GPM from that connection in the basement. According to the city and my crude "fill a 5gallon bucket with a hose" test, I should be getting closer to 20-21 GPM.

Any suggestions? Should I have the entire basement setup redone? It seems to my untrained brain that going from 3/4" to 1/2" then back to 3/4" would jack with the pressure but I don't know. A buddy of mine suggested running the sprinkler supply line off the 3/4 main before it reduces down to 1/2". I'm at the point of near desperation: the city we live in gave us until the end of September to have our front yard completed (sod, trees, etc) so I'm trying to be somewhat quick about it to avoid a fine.

Any help would be appreciated. If I have to dig up the yard and tap into the main before it enters the house, so be it. If adding pics would help clarify my ramblings, I can do that.

Thanks in advance, new friends.

Central Irrigation

Supreme Member

Posts: 371

Location: Central Minnesota

2

Sunday, July 26th 2015, 6:56pm

Where is the pressure regulator set?

jaguavai

New Member

3

Monday, July 27th 2015, 8:22am

CI

Thanks for your reply! The one inside the basement is set at 60, or so I've been told. I haven't had any trouble with indoor fixtures yet.

Central Irrigation

Supreme Member

Posts: 371

Location: Central Minnesota

4

Tuesday, July 28th 2015, 5:26pm

There is no place for a 1/2" line trying to feed a sprinkler system. Although, a few inches of it may not cause all that much problem. From your description, it sounds as though the regulator is before the sprinkler supply line, is that correct? It is possible that is not set correctly or faulty. You would need a pressure gauge to test actual pressure. Certain shut off valves can cause constriction points in a supply line also. Waste and Stop valves get cut out of supply lines on a regular basis.

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