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wsommariva

Supreme Member

Posts: 332

Location: Northern New Jersey

31

Tuesday, April 12th 2011, 4:54pm

Thanks for that info. My system is city water dynamic psi low 40s. GPM from 3/4 line 5.5

Three zones 5 heads....17 ft radius spray.

All heads have good pressure and coverage.

I have auto drain valves.

I think the PVB gush problem I had was due to the auto drain.

Was during install testing.

Don't think I have a valve manifold poblem as I constructed it well

Propery is flat

I'll put in a PVB and if I have troubl
e I'll let you know.

So should I get the Wilkins or Febco

Sory for messy post..its from my phone

Wet_Boots

Supreme Member

Posts: 4,080

Location: Metro NYC

32

Tuesday, April 12th 2011, 5:49pm

If your supply only gives you 5.5 gpm at 40 psi, are you certain you can run 5 sprays per zone? Conventional spray heads that shoot 15 feet use over 1.8 gpm on a half-circle pattern. Five half-circle sprays would use 9 gpm. You may be overdrawing your supply, and drain-valve-removal might not be a complete cure.

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I don't think you look to change the supply plumbing (PVB) until the zones are in order. By the way, a zone flow of 5.5 gpm is one where you you would want to use the flow controls on the zone valves, in order to have them last longer and operate more reliably, and, most importantly, close faster, which may eliminate the overlap time of two zones open at the same time, which is the usual point of having water spill from a PVB

wsommariva

Supreme Member

Posts: 332

Location: Northern New Jersey

33

Tuesday, April 12th 2011, 6:22pm

No I have three zones and 5 total heads for the entire system. Zone 1 and 3 have two heads each and zone 2 has only one head. Total GPM useage per zone is well under 5.5.

Wet_Boots

Supreme Member

Posts: 4,080

Location: Metro NYC

34

Tuesday, April 12th 2011, 8:04pm

Even more than before, you need zone valves with flow controls, and I am going to assume yours don't have them. That is the very first detail to attend to. You can't have reliable valve operation at low flows, unless you throttle down zone valve flow controls. They limit the movement of valve internal parts, and make closing faster and more reliable. If a zone valve opens only enough to allow a 5-6 gpm flow, that may be enough to take care of any PVB spillage.

hi.todd

Supreme Member

Posts: 417

Location: Houston, Texas

35

Tuesday, April 12th 2011, 11:33pm

:thumbsup:
:thumbup: :thumbsup:

wsommariva

Supreme Member

Posts: 332

Location: Northern New Jersey

36

Wednesday, April 13th 2011, 6:34am

OK I'll put in valve controls put in a better PVB and I should be ok. Is it one control per valve or can I get a one control for all 3 valves?


EDIT.....I need new valves with built in flow control. Will rainbird valves work with a Toro timer?

This post has been edited 1 times, last edit by "wsommariva" (Apr 13th 2011, 7:06am)


Wet_Boots

Supreme Member

Posts: 4,080

Location: Metro NYC

37

Wednesday, April 13th 2011, 7:30am

Take care of the zone valves first. Leave the PVB for last, if it all. No problem combining different makes of valves and controller. Once you have things so a zone opens without spillage from the PVB, you then see that you can run through a cycle without any spillage. You might still have to remove the drain valves.

-

If you want to make all this into a "learning moment" you can get a pressure gauge and connect it to the supply, and observe pressures during operation.

wsommariva

Supreme Member

Posts: 332

Location: Northern New Jersey

38

Wednesday, April 13th 2011, 7:46am

Ok I think I'm all set. If I have any problems I'll let you know.

Thanks again for the assistance



EDIT: Toro doesn't not have flow control valves. The valves I have are "low flow" valves. "closes at low flow, ideal for drip". "operates as low as .5 GPM" Can I stick with these valves and see if they work with the new PVB?

This post has been edited 2 times, last edit by "wsommariva" (Apr 13th 2011, 10:10am)


Wet_Boots

Supreme Member

Posts: 4,080

Location: Metro NYC

39

Thursday, April 14th 2011, 3:08pm

Toro does make flow-control valves. If by some chance you used the 3/4-inch valves that are sold in home centers, you can't upgrade them. Only by throttling down a valve's flow control do you greatly improve its closing speed.

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Is this all home center equipment? Does the PVB spill every time you turn on a zone? Does it spill only when you cycle from zone to zone? There is a possibility you can deal with the latter by way of controller programming.

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Nothing you have posted indicates the problem is the PVB. Any PVB will spill when the pressure drops low enough. For what it's worth, the Wilkins 720 is far more likely to reseat itself after a temporary pressure drop. But if you make the system function properly, you don't have those pressure drops in the first place.

wsommariva

Supreme Member

Posts: 332

Location: Northern New Jersey

40

Thursday, April 14th 2011, 3:48pm

I bought everything from Toro.com. Homeowner residential products. I do have 3/4" valves. I had just one problem with the PVB, it freaked me out and asked for help here. I don't think it's the PVB, it was my lack of knowledge.

I bought a new brass PVB. I'll put it in, remove my auto drain valves and test the system. I'll let you know if I have any problems.

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