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Jflow66

New Member

1

Sunday, July 16th 2017, 11:11pm

Advice on My Franken-Manifold

Hello Pros,

For the 4th or 5th time now, I have a blowout in my manifold, and I am faced with the repair or rebuild decision!?! Obviously, I have some issues, given this keeps happening. I had just replaced 4 rotor heads on the busted zone, as well, so perhaps I decreased the output in the heads, enough for it to bust? Speculating only. Or maybe a bad repair fitting from the previous repair?

Manifold is also right at my front door and I would love to move it away, closer to the water main, but the zone lines end where they end, right?, and the main line goes under the walkway, too. Certainly, there are many factors involved in planning the optimal design, but given the state I am in, any advice from the pros is much appreciated.


I am in the East Bay, CA. Thank you. :S

Wet_Boots

Supreme Member

Posts: 5,147

Location: Metro NYC

2

Monday, July 17th 2017, 5:38am

California sprinkler plumbing can look like that. You might be more specific as to what you mean by "blowout" and to which of the valves this occurred.

Jflow66

New Member

3

Monday, July 17th 2017, 6:28pm

Yeah, there's a red arrow on the first pic, but here's a closer look. Thanks.


Wet_Boots

Supreme Member

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Location: Metro NYC

4

Monday, July 17th 2017, 6:55pm

How old is the system? Above-ground plastic plumbing can possibly get brittle from decades of sun exposure. I'm guessing you probably have high water pressure. High water pressure plus valves that close very quickly can create a water hammer force that might be damaging to plumbing.

mrfixit

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Posts: 2,002

Location: USA

5

Tuesday, July 18th 2017, 10:59am

Let me put in my two cents. I live in Cal.

A broken coupling like that is HIGHLY unusual unless he pipe is under a lot of stress. It could be someone kicked it.

I suppose very old fittings might have been used.

If I was your sprinkler guy, I'd rebuild the whole thing since this is an ongoing problem. I'd install all the same valve. The valve on the right is the one I'd use. It's a 1" 2713APR I believe. If the pipes are 3/4" then it's a 2711APR.

Don't use Lasco fittings. Go to the Home Depot. They have Dura which is a much better fitting in my opinion. I like the deep sockets. Make sure you us primer on the pipes before gluing. Don't forget the teflon tape for the male adapters.

This part is important. Do not force the pipes that connect to the valve. They need to be the correct distance apart. Look at the two valves you have on the right of that manifold. One's a Rainbird ASV and one's an Irritrol. There's a dramatic difference between the distance of the two ports on each valve. The three valves on the left are somewhere in between those two. So you have three different valves all of different widths.

If there's a dramatic water hammer happening, you might want to upgrade to the Superior/Buckner 800 brass valves. They shut off nice n slow cutting down or eliminating the water hammer all together. They're four times the cost though including the brass valve body. If you use those let me know. There's something I want you to do to them.

I'm not a fan of the Jar tops installed on the left. They have a tendency to leak.

So I'm saying to start over and pay close attention to detail.

One more thing, pvc glue and water do NOT mix. The pipes must be dry during the gluing process.

Wet_Boots

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Posts: 5,147

Location: Metro NYC

6

Tuesday, July 18th 2017, 1:41pm

I have used the inline version of the jartop valve shown in the photos, up to a certain amount of pressure, and for 100 psi pressures, I switched to the one on the right, with 8 cover screws. I noticed that the jartop version could close with more of a hammer than the other one. If only the jartop valve plumbing is breaking, then that's a clue that you might have water hammer.

One thought on re-plumbing the valves. There is a plumbing item that is far stronger than what is in the photos. It's called a TOE nipple. It would replace the above-ground pipe and male adapter on the upstream side of the valve, giving you as durable a manifold as you could want. Many pros that use TOE nipples don't actually buy them that way, as TOE nipples, but buy regular nipples double the length they need, and cut them in half (they just have to be certain they are working with machined-from-pipe nipples and not from-a-mold nipples, as the latter won't cut into TOE nipples)

And one long-ago observation on the 800 series valve from Superior, that may only apply to cold-winter locations. We had leaks from around the flow-control handles on the Superior 800 series, and found that the O-rings needed replacing. It was suspected that freezing water was at fault (even though the systems were properly winterized) and that this was something the (located in Southern California) Superior company hadn't noticed when they designed the valve, given where their customer base is for these types of valves.

mrfixit

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7

Tuesday, July 18th 2017, 1:50pm

You're right. The leaking around the stem is probably due to freezing. I don't see that problem here. The O-ring in there is very tiny.

Wet_Boots

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Location: Metro NYC

8

Wednesday, July 19th 2017, 5:14pm

You're right. The leaking around the stem is probably due to freezing. I don't see that problem here. The O-ring in there is very tiny.
I thought I'd mention it just to add to the knowledge base, in case the valve hadn't changed at all (it probably merits a bigger O-ring) ~ My old favorite ASV (the R711) got a slight remake from Hardie, and they almost all started leaking from around the flow control stem, and thank-you to Toro for the design fix I can see at work today in the Irritrol 205TF

Jflow66

New Member

9

Thursday, July 20th 2017, 12:10am

Thanks very much Gents. Nice of you to help out a noob, like me. Never heard of toe nipples and water hammers before, but I think I get the message.

The system is at least 20 years old and we have never had a cover for it, so 100+ summer sun for 20+ years. Yes, I will be covering it after I am done with the rebuild. And yes, it does seem to be only the jartop valve plumbing that is breaking.

  1. Investigate Pressure Reducing Valve/ Pressure Regulating Valve/ Pressure Regulator (I appear to have one and it likely requires adjustment).
  2. Rebuild with Irritrol 2713APR - 1 inch + use Dura pvc, as mrfixit says.
  3. Get cover, Use cover.

I also just found https://www.irrigationtutorials.com/inst…i-siphon-valve/ which seems to have a picture of that extruded pipe upstream toe nipple into the valve setup. I think that's what you meant, Wet_Boots.

Thanks very much. :thumbup:

This post has been edited 2 times, last edit by "Wet_Boots" (Jul 20th 2017, 8:49pm)


Wet_Boots

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Location: Metro NYC

10

Thursday, July 20th 2017, 8:44pm

I fixed the link (it's a site flaw) for the tutorials page. It is a little simplistic, and less technically correct than it is practical. It happens that there is not a prohibition against the use of non-metal plumbing upstream of the valves. Practicality is you looking at the broken plumbing and thinking this wouldn't have happened if that material was steel or copper. The trades have PVC in successful usage for half a century or more in pressure plumbing applications.

A lot of California irrigation is decades old, and has received a great deal of sunlight. Age and UV exposure has helped some of it become brittle. All on its own, the sch 40 PVC pipe and fittings are not a danger to blow apart even with hammering zone valves, so long as the supply pressure is not extreme. You do want to measure your supply pressure, and if need be, adjust the pressure reducing valve. If the pressure can be kept low, you won't have any real need to replace still-working valves.

So far as protecting new PVC plumbing goes, a coat of spray paint will block UV rays. Solvent-based paint (like Krylon) is better than brush-on latex paint, so far as future maintenance goes, since the spray paint is easily removed with pipe cleaner, in case a repair is needed.

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