# ANOTHER irrigation problem..sigh



## ktgrok (May 25, 2019)

This has been the project from hell. Anyway...I've finished working on 3 of the zones, now doing the last one, in the backyard. (actually, it is zone 1, but whatever). Got the lines, risers, heads installed. Wired the valve back in as until recently there was nothing working on zone 1 - previous home owner capped it off when they installed a pool that took out a bunch of lines - so hadn't been connected. And....way low pressure. Even without the heads on, when I was just flushing out the pipe/risers, low pressure. I get good pressure for the first three sprinklers, then very little for the rest. 
I've dug up the pipe (some wasn't even buried yet that I had replaced) and no leaks that I can find.

could it be either a bad valve (already replaced two others, so possible) or a clog in the pipe between the sprinklers that work and the ones that don't? I know dirt got into the pipe, and that's why I was careful to flush it out, but maybe there is a rock or twig in there?

updated: I cut the pipe there and there is nothing clogging it. It's just low flow...so either a leak in the area between the valve and the first sprinkler (only area I didn't dig back up, as it has grass seed germinating on it) or the valve. i did dig that pipe up recently and visually it looked fine.


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## g-man (Jun 15, 2017)

What about swapping the internals of the valve with another valve. At least it will be better than digging more pipes.


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## ktgrok (May 25, 2019)

g-man said:


> What about swapping the internals of the valve with another valve. At least it will be better than digging more pipes.


I can't because it is the only Rain bird valve, the others are lawn genie valves. (I have to find them on amazon now, no longer made/sold).

Lowes has the replacement valve for about $20, in stock, so I'll pick one up in the morning and swap out the top parts (bonnet, diaphragm, solenoid, etc).


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## Delmarva Keith (May 12, 2018)

As far as diagnostic technique, a lot easier to replace a valve to rule out old faulty valve than dig up pipe. An old valve with unknown history, just replace it entirely. Also a lot easier to plug risers and test for flow to rule out suspected leak than dig up pipe.


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## ktgrok (May 25, 2019)

Ok, so replaced the valve, no change. Sigh, I really really really was hoping that would fix it.

Next is to plug the risers and see what I can figure out. Oh, and going to snake one stretch that might be the issue. Then going to I guess dig up the one section of pipe I haven't checked, that is in the area I went over with the tiller last week. So possible I hit it with the tiller, although I tried to stay very shallow. Will mess up my grass that is growing which angers me to no end. Then, if no leak, only other thing to do is redo everything with bigger diameter pipe. I have zones in the front that are mostly 1/2 for long stretches, so repeated that in the back since 1/2 inch pipe is so much easier to cut and I've got joint pain/swelling in my hands. But it may just not be enough room for the water. Blergh. Mostly annoyed that this may be a self inflicted problem.


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## ktgrok (May 25, 2019)

Oh, wait - if I cap it all off, and check the meter, and the meter is still running...that means a leak in the system, right? And if it isn't running, then no leak, don't dig up the pipe, right? Like, I already checked all the pipes from the first sprinkler through the last, so if I were to quickly cut that pipe and cap it, then turn the zone on, nothing should happen, but if after a minute the meter shows water running, that means it is leaking between the valve/manifold and the first sprinkler, right? That bit of pipe is pretty shallow and easy to get to, right before the first sprinkler head, so not hard to do, and easy enough to reconnect it.


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## Delmarva Keith (May 12, 2018)

ktgrok said:


> Oh, wait - if I cap it all off, and check the meter, and the meter is still running...that means a leak in the system, right? And if it isn't running, then no leak, don't dig up the pipe, right? Like, I already checked all the pipes from the first sprinkler through the last, so if I were to quickly cut that pipe and cap it, then turn the zone on, nothing should happen, but if after a minute the meter shows water running, that means it is leaking between the valve/manifold and the first sprinkler, right? That bit of pipe is pretty shallow and easy to get to, right before the first sprinkler head, so not hard to do, and easy enough to reconnect it.


Turn off all fixtures in the house. Seal the pipe (you can just cap the risers) except for an open manual valve on the farthest end. Turn on the zone. The pressure differential will allow the zone valve to open. Make sure water flows out the end of your manual valve. Close the manual valve. Mark the water meter pointer. Wait about 15 minutes. Water meter pointer should not move. If it does, you have a leak.


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## ktgrok (May 25, 2019)

Thanks. Will pick up some caps to cap the risers. What kind of manual valve do you mean? Need to know what to look for. Will the zone valve not turn on if I have everything capped off versus a valve open at the end?


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## Delmarva Keith (May 12, 2018)

ktgrok said:


> Thanks. Will pick up some caps to cap the risers. What kind of manual valve do you mean? Need to know what to look for. Will the zone valve not turn on if I have everything capped off versus a valve open at the end?


Your sprinkler heads have either 1/2" or 3/4" threads. Whatever the last head on the line has, pick up a ball valve that will thread on. Ordinarily the risers have male threads and the head has female threads so get a female threaded ball valve of the appropriate size.

If the pipe is sealed or has a tiny leak the zone valve might not open. It needs some amount of pressure differential (incoming water pressure on the inlet versus open nozzles or some opening on the outlet) to open. Likewise it needs differential to close (not your current problem). You also want to make sure the line has flow so might as well check it all at once. You might be surprised what flushes out of the line at the end.


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## ktgrok (May 25, 2019)

Thank you! Placed an order to pick up at Home Depot, including the valve. Will give it a try later today. If no leaks, and nothing comes rushing out, then I'll be redoing it with bigger pipe. Which is a PIA, actually more a pain in the hands since it is so much harder for me to cut, but not truly hard.


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## Delmarva Keith (May 12, 2018)

ktgrok said:


> Thank you! Placed an order to pick up at Home Depot, including the valve. Will give it a try later today. If no leaks, and nothing comes rushing out, then I'll be redoing it with bigger pipe. Which is a PIA, actually more a pain in the hands since it is so much harder for me to cut, but not truly hard.


Well as another idea to try to shortcut ruling things out, if you get to the point where you really think flow capacity of the pipe is the issue and nothing left but to dig, lay the new pipe, risers and heads out above ground, hook it all up as if you were done and turn it on. If it still no worky, don't dig; it's something else going on.

You can also pencil whip flow rates and pipe capacity (a little more involved than can be explained on a message board). If flow capacity is the issue, you almost certainly don't need to replace all of the underground pipe. Think of it maybe like a tree. The trunk at the ground feeds the entire tree and needs to be big. As it moves along upward, fewer and fewer branches feed off that same trunk and it can get smaller.


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## ktgrok (May 25, 2019)

I'm lucky in that most of the pipe is already up for me checking it, just a section of it that isn't. And that section is 1 inch pipe so I'm not worried about that. So if flow rate is the problem it won't be too hard to replace, and yes, I think there's just one major stretch I need to replace.If that's the problem I'm just annoyed at myself for not doing it right the first time, LOL. But I guess that's how you learn.


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## g-man (Jun 15, 2017)

One option is to T close to the valve and just run a second line further down the chain and T again there. This will provide more cross sectional area for water flow at a reduced friction loss. (Aka Hardy Cross method)


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## ktgrok (May 25, 2019)

Ok, so no leaks, at least the water meter ran VERY VERY Slowly..but I did have risers that were dripping/leaking water at the caps. And when I had everything but the last one capped off the flow was no where near as strong as it should be. So there is either a true clog somewhere, or just too much friction/not enough flow. Going to replace the pipe that runs from the side with the valves over to the side of the yard where most of the heads are, but shouldn't need to replace the lines over there I don't think - as others said, if I can get the tree trunk bigger the branches should be okay. And if it's a clog, well, I'll be cutting it out, lol.


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## g-man (Jun 15, 2017)

Whats your gpm on that zone, your pressure and design gpm?


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## ktgrok (May 25, 2019)

it works!!!!! Replaced most of the pipe with bigger diameter pvc and voila! I do think there might have been a clog somewhere, as when i flushed it out this time a big flush of water came out, then stopped, then gurgled, then a bunch of brown water and then it was flowing properly. So maybe some of what I didn't replace was clogged, and putting bigger pipe in front of it allowed enough flow to dislodge it, or who knows. But it works! I was doing the happy dance for sure. (now need to rebury all the darned pipe, cut the risers to the right height, etc etc...but it works, darn it!)


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## g-man (Jun 15, 2017)

:thumbup:


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## Delmarva Keith (May 12, 2018)

ktgrok said:


> it works!!!!! Replaced most of the pipe with bigger diameter pvc and voila! I do think there might have been a clog somewhere, as when i flushed it out this time a big flush of water came out, then stopped, then gurgled, then a bunch of brown water and then it was flowing properly. So maybe some of what I didn't replace was clogged, and putting bigger pipe in front of it allowed enough flow to dislodge it, or who knows. But it works! I was doing the happy dance for sure. (now need to rebury all the darned pipe, cut the risers to the right height, etc etc...but it works, darn it!)


Well done!

On the risers, using flex pipe (funny pipe) for risers is a lot easier than fixed risers that have to be cut for height. Premade swing joints are another convenient option too.


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