Severe Continuous Pipe Vibration When Valve(s) Open

[goof99]

Water dept was here in less than an hour. A new meter is going in tomorrow. He listened to the meter and said he could hear it rattling. He said the Badger was his favorite meter. It has a plastic rotor which does wear out. The new meter will be the piston type. If that doesn't stop the vibration, "We'll go from there."

Guy was really nice. I thot I'd have to plead my case like in a court of law. Not at all. Like you guys he works with it all the time, if he hasn't seen it it hasn't happened.

Will letcha know.

Ifx- I concede the wisdom of your experience. Much simpler. Just as effective. I usually have to work overtime to devise something simple. :>)

 

[Chris]

I hope that fixes it, you are running out of moving parts to check.

 

[goof99]

New meter. Same vibration. Nothing left to do but stand in the kitchen and eat everything in sight.

I am going to isolate the supply line anyway to completely remove all doubt because I'm not totally convinced. Had to knock that drawing down a lot to get it on board so it may be hard to read.

Two other clues?

1. With the water running in any circuit and pipes vibrating I can close the main shutoff valve partly or completely till the vibration stops then open it very very slowly and get that circuit flowing with no vibration. Open fast and it vibrates.

After that if I crack the hose bib open with a pressure gage on it the vibration may start again. That's a damn small perturbation to start the system vibrating. Especially when the water is not flowing thru the copper pipe on which the bib is mounted.

2. The front yard has 6 circuits sequenced on the clock 1,2,3,4,5,6.

a. If I run the sequence in that order 1 & 2 vibrate, the others do not.
b. If I run the sequence 4,3,2,1,5,6 then 4 & 3 vibrate, the others not.
c. If I run the sequence 5,2,3,4,1,6 then 5 & 2 vibrate. the others not.

So the first two circuits vibrate regardless of sequence.

I upped the water-off pressure from 45 psi back to 60 psi for practical in-house water flow. With water running the static pressure is about 20 psi. The water dept guy thot I had too many 90º turns in the sprinkler circuit manifolds and so do I but it didn't vibrate for 25 years with the same config. Short of a backhoe and bull dozer I can't change much. Remember the system vibrates as a whole.

Guess that's about it. I won't bother you with more unless I get it solved. Thanx for all suggestions and comments.

 

[IFIXH20]

Does the back yard under house line connect to the hose bibb and the service ? -- where is your BFP ?

 

[phishfood]

It sounds for all the world like a loose rubber washer flopping in the breeze. But with your description of your system, I just don't see where. Maybe there is another ancient valve before the meter somewhere that you don't know about?

 

[goof99]

Progress!

1. I disconnected the sprinkler lines front, garden and back completely from the house, physically and hydraulically, the pipes didn't even touch. Turned on each of the 3 hose bibs separately and the system vibrated. So!!!!!

2. I disconnected the sooply line just downstream of the PRV (between the house and the PRV) and hooked up a simulated household pipe system (SHPS)*. It was about 23-4 feet of 3/4 PVC pipe with a PVC gate type valve glued on the end. It did not even touch the house pipes. No physical or hydraulic connection. Turned on the water, opened the valve and it uh - well it uh - well I'll be damned, the darn thing vibrated.

I decided to use a long pipe section so that any vibrations would create a fairly large amplitude and be easier to detect. They could be felt as well as heard. Thus making it easier to prove to the city.

Therefore the problem is NOT in the house or any of its components - it is in the supply to the house. Now it may be in the line between the street and the house which is my responsibility, not the city's, but it may be in the line upstream of the meter which is the city's problem. The meter man is scheduled to phone me Monday morning.

I'm just happier than a pig in sh*t because my analysis was vindicated.

Just for completeness I did redo the experiment w/o the new PRV (tapped in just upstream of the PRV - between the PRV and the street) and got the same result at full city pressure proving that my new PRV was good and the vibration is independent of the PRV. It is a Wilkins which I gather is a good brand even if I did buy it at Lowes.

So now with this new info what might the matter be? Assuming the new meter is good I'm wondering if there might be a stone or some such object in the supply pipe. This is hard to believe because I did definitely run water thru the pipe to flush it before plumbing it to the house when I rebuilt the front sprinkler manifold 3 years ago.

*Simulated Household Investigative Tool (SH*T)

 

[Chris]

What water district is it? I may be able to look up there service and see what parts they use and give you a better idea of what may be wrong.

I find it hard to believe an angle meter stop or customer service valve would go out since they are ball type but stranger things have happened.

 

[goof99]

City of Redding California.

Reading thru their site I see they have a Polybutylene Replacement Program. I'm wondering if there might be an outside chance that was used between the main and the service connection at the meter. If that degraded and a piece broke loose inside the pipe and fetched up against the meter connection or on/off valve or resulted in a flap inside the pipe it might conceivably cause my problem. Obviously that's a wild guess. Might be better than no guess. Might be plain crazy.

I'll ask em Monday.

 

[Chris]

Here is a link to your water service. It looks pretty standard. I'll look more into it tomorrow.

http://www.ci.redding.ca.us/pubworks/eng/pdf/40100R03.pdf

 

[goof99]

Polybutylene Replacement Program
http://www.ci.redding.ca.us/water/distrib.html

About the middle of the page.
========
Looks like page 400.00 might confirm that polybutylene could have been used.
========
I tried to check the meter inlet pipe material but it is vertical below the meter. Digging down at best I'd get a finger on it. Unless I dug a great big hole next to and under the concrete shield box. So can't tell if it is polybutylene.

After some thot if the polybutylene pipes deteriorate and leak it seems to me there could be a thin section or delaminated section in that pipe that could be undergoing a collapsing and recovery oscillation causing a vibration.

A sudden valve opening would create a strong pressure reduction wave traveling back thru the system. This might trigger the thin place to begin oscillating. As noted above if I very very gradually open the supply valve at the house the vibration may not occur. This could occur because there would be only a slight or very low magnitude pressure reduction which would inhibit (be below the threshold of) the onset of oscillation.

Further, and this might be a bit wild, but the vibration sometimes stops by itself which conceivably could be due to the thin spot work hardening. Or a delamination temporarily filling with water. This could possibly explain the sequencing observations in a previous post.

Somehow I think all this is more reasonable than a loose piece or flap.

If this is what has happened I can't help wondering where the deteriorated polybutylene has gone - like down my gullet?

 

[Chris]

You could be right. You have ruled out damn near everything else. Unless there is a small piece of trash stuck in there. Sometimes when we tie in there will be chunks of wood and other debris from construction going on nearby.

 

[goof99]

I ain't forgot the followup here.

The City hasn't got back to me yet. There were 3 meter men and now just one so it may be a while before this gets fixed up. I'll post what happens when/if it gets resolved.

 

[goof99]

Ahh So!

Look what I found buried in the Saw Grass. Pressure regulator been buried in the ground since 1981. Nobody knew it was there. The box was buried under a big growth of Saw Grass all these years. What made me look?

Well the system quit vibrating. Hmm. For some reason I decided to dig down and check for sure we had polybutylene pipe between the meter and the main. I noticed the downstream end of the inside of the box was wet. I dug around with a screwdriver and it almost fell thru. Further digging revealed it was hollow behind the meter box. I dug off about a 6" thick mat of 2-3 foot tall saw grass and found a circular concrete box. Inside the box a pressure regulator. Not only that the water was leaking from the pvc adapter leading in to the regulator. It was split.

Well the leak occurred after they installed the new meter so they musta tweaked the pipe and caused that. Maybe the vibration caused the crack. That's what I think. Anyway it looks to be leaking about 1/2 gpm; just eyeballing it from other measurements I've made, and that would explain the end of the vibrating.

Of course, the old regulator is suspect based on all your comments obviously borne of much experience. City is scheduled out tomorrow morning and maybe they will fix it and maybe they will say tough luck MFR. Either way a new regulator will be installed sometime tomorrow. That will put 2 regulators in the supply line. That way the underground PVC supply to the house will not be over pressured and the final tweaking of the pressure will be at the 2nd regulator next to the house.

I'll let you know how it all works out.

 

[goof99]

There are 4 meters in a row maybe 1.5 feet apart for 4 houses on a private drive and this so far appears to be the only one with a regulator just downstream of the meter. Mine is the 1st house and the pipe is about 80' to the house. The next pipe runs about 250' to the next house. Last house is about 600' or so. Might that explain a lack of regulators?

 

[phishfood]

I would get rid of that regulator, so that you only have one to worry about maintaining. And even if you do keep it, get rid of those PVC female adaptors, they are famous for splitting.

 

[speedbump]

And even if you do keep it, get rid of those PVC female adaptors, they are famous for splitting.

I'll second that!

 

[goof99]

Where to start? Lots to cover.

Pics. You can see the new install - no PVC females.

I opened up the old regulator (45 minutes) just to see. Nothing looked broke just old. Spring was strong. Diaphragm not broke. You can see the screen is a bit plugged to say the least. I found the cotter pin inside the valve. Looks like whatever it was in rotted away and went down my gullet. No idea if that pin caused the problem.

The split was in a male adapter and is tiny. I think it was shooting maybe 1 qt/minute if that.

2 PRV's. I decided to put one in because I don't know why it was originally used. Doing it this way was easier for me at the moment - I have several other problems - this vibration has been a nightmare since spring. Mine was the first house built and maybe it was for construction pressure control before the house was plumbed. Just guessing. I may remove it. At this point I don't give a ripping damn - that vibration is gone. I hope. It got to where I would wake up when it stopped wondering what was wrong.

Incidentally the leak did not alleviate the vibration as I stated in a previous post because it did chatter Tuesday morning. It never was consistent. I ran the front yard sprinkler system this morning and no chatter. Tried lots of other tests too.

3. Since noon yesterday there has been no vibration.

4. The city never did show up yesterday so I went ahead on it myself. We thot maybe installing the new meter had tweaked the pipe causing the leak. I doubt it. I think the vibration did it. I am happy that I didn't have to try to argue with em about how the split occurred because I didn't truly think it was their fault anyway.

5. So at this point I am cautiously optimistic, as they say, and will wait for a couple weeks before celebrating.

Thanks again for all suggestions and apparently they were mostly correct in that it was a valve at fault. You guy know your stuff for sure but who'd a thot there would be an unknown unneeded valve buried someplace.

 

[phishfood]

I have started using Schedule 80 PVC male adaptors in situations like that. Male adaptors aren't as problematic as female adaptors, but I still have seen too many of the Schedule 40 ones crack under moderate stress.

Fingers crossed hoping that your vibration problem is now solved.

 

[dungbuster]

Yes you have air in your system causing jackhammer effect. I would need a schematic to help u out.

 

[speedbump]

That's a very odd place for a split in a male adapter. Almost looks like something sharp was pushed into the plastic. Those males generally break at the threads before they go bad anywhere else.