Severe Continuous Pipe Vibration When Valve(s) Open

[goof99]

I've wrote this up several times and tried to be brief and concise but it seems to get longer and longer because there are so many ifs. I hope this boiled down version paints the picture. I have studied this intensely on the internet, tried lots of combinations of things, spent many hours messing with it. Any and all ideas welcome.


Copper pipe under house vibrated SEVERELY. Shook the house, rattled the dishes in the cupboards. This was not a couple bangs like water hammer it is continuous like a jack hammer. It does not stop until I flush a toilet or sometimes open a hose bib for a minute or less.

It ONLY happens when valve(s) open.

Only with opening of these valves; sprinkler mostly, toilet & washing machine rarely. Inside faucets do not initiate vibration.

After reducing pressure from about 120 psi to about 50 psi (installed a PRV) the problem is reduced to this: Intensity of vibration vastly reduced.

There are 17 sprinkler valves. Any one may or may not trigger the vibration. The house was built in 1981 and the sprinkler systems installed mostly in 1982. Some valves have never been replaced. There wasn't a peep from the pipes till this summer.

The sprinkler circuits T off the main line upstream from the main house. The vibrating pipe doesn't even have water flowing thru it. The pipe is all PVC up to the house where it transits to 3/4 copper.

My conclusions are:

1. High pressure by itself is not the problem.
2. Loose pipes are not the problem.
3. Something obviously changed but what I cannot imagine
4. Air in the pipes must be the prime problem.

 

[Chris]

So it starts when a valve opens and it continues even after the valve is shut and everything is pressurized? Even with no water moving? Or is it only when the valve is open?

If your pipes are fully secure and can not move how do they vibrate? Maybe there is a loose pipe somewhere in a wall or something that you have not checked?

 

[IFIXH20]

Run your sprinklers with the service entrance valve off ( the shutoff valve for the house water only) to see if the vibration occurs.

 

[goof99]

hi- Only when water is running - valve open. Shutting the valve stops the vibration.

The pipes are about as secure as they can reasonably be. Crawling under the house and holding pushing pulling the main pipe I cannot stop the vibration. I did tie down the offshoot pipe to one toilet which was vibrating so bad it was a blur. You can bet it is now clamped down damn good and solid. I've tried pushing/pulling on all the pipes to check the hangars and they are snug.

But the main feeder pipe has an internal vibration. And, of course, a vibration will transmit along. Even if pipe was loose I shouldn't think it would vibrate continuously.

Here is another complication: In the front yard, for example, the 1st valve on will vibrate. The 2nd will vibrate some less. 3rd thru 6th valve no vibration. Changing the valve sequence does not alter that scenario. Only the underhouse pipe is vibrating; the sprinkler pipe/valve combination is not.

Couple nights ago my wife flushed the toilet and turned on the shower same time and the vibration occurred but stopped when the toilet ended its fill. All that water went thru the copper main line.

Lotsa ifs.....

 

[IFIXH20]

Shutting off the Service Entrance Valve ( Main water valve for house water only) stops the vibration when the sprinklers are on , Right. What type of service entrance valve (Main water valve) do you have . (ie. gate valve, ball valve).

 

[goof99]

IFIXJH2O

I recently re-plumbed it and can't do that now as there is just one main shutoff. I can shut off the separate sprinkler circuits which doesn't help. I had previously tried to do what you suggest but at that time I couldn't quite shut off the house because as it turned out the shutoff valve had solder in it from the original sweat installation 1981. Nice to discover after 30 years. It got down to a small dribble but eventually the pressure would come back up and the vibration start. So that test was only a partial success.

 

[goof99]

Ball valve. PVC. Original was brass gate valve.

 

[IFIXH20]

Do you have a Backflow on the sprinkler system, or a check valve on the house side

 

[goof99]

Basically no. But the garden does have a BFP for the 3 valves of which only 2 are used. It's been buried for 20+ years. it's at least 35 ft from the back of the house.

Even the street meter feels the vibration and its about 80 ft away.

 

[IFIXH20]

The problem could be in the BFP. I have seen backflow preventer on hydrants cause water hammer through out the house when the hydrant is on.

 

[IFIXH20]

Post a diagram or photos of your system from the water meter to the house and sprinkler system

 

[goof99]

As it happens the water to the garden is the only circuit running thru the house. I tapped off a hose bib thru a gate valve to the garden thus thru the BFP. I shut that valve, double checked that it did fully stop the flow and turned on the front sprinkler circuits. Still vibrates. I believe I had done that before. In fact I now recall turning it off during a vibration and the vibration did not stop. Too bad - Ida been out there digging it out in the dark.

I kept a log at one time but it's beyond reading anymore. You wind up spending more time writing than doing.

 

[goof99]

I think I've found the answer. Have to leave for this weekend. Will come back couple days and run it past you - see what you think.
Thanx for comments so far.

 

[goof99]

Ok. Back from a trip on the Sacramento Freeway System. 60 mpg speed limit, 80 mph preferred, previous experience mandatory.

This is kind of long.

I got the system vibrating, crawled under to tighten and brace etc and the vibration stopped while I was working on it. Now wouldn't that frost ya? Anyway I fininshed that task and started the water going again, crawlwd under to check things out. The noise was vastly reduced. The vibration itself still there. While I was holding the vibrating pipe it ceased. Then I could feel it throb weakly occasionally like it wanted to start again. I arrived at the following conclusions:

First there are 2 pipes under the house; 1) the copper that feeds the house and 2) a pvc that feeds the back yard sprinkler manifold. Both vibrate. Both flow directly from the main supply pipe to the house from the street.

1) The initial vibration occurred at system pressure 120 psi. Cutting that to 45 psi did not eliminate the vibration. Lower intensity yes eliminate no. Therefore the vibration was not caused by high pressure.

2) The vibration occured both before and after installation of a new PRV. Therefore it was not caused by the PRV valve.

2a) The shutoff valve is a new pvc ball valve which cannot rattle therefore the vibration is not cause by the shutoff valve.

3) With front yard sprinkler actuated the system vibrated even w/o water flowing thru those under house pipes, copper or pvc.

4) With back yard sprinkler actuated the system vubrated with water flowing thru the PVC but not the copper.

5) The garden watering does flow thru the copper pipe. With the garden sprinkler actuated the system vibrated with water flowing thru the copper but not the pvc.

6) Therefore the source of the vibration is upstream of the entire house system. It is between the street and the house.

7) When the system is vibrating it can be felt on the meter. The locally observed vibration amplitude or intensity at any particular point in the system would be dependent on just how that section of pipe was constrained or supported just like a vibrating string.

8) Therefore the meter at the street is generating the vibration. Since the problem started just recently something in the meter has changed.

To prove this I will have to connect and actuate a simulated pipe system above ground in the front yard and completely break all physical connection with the house system. As I visualize it would have a 20' pvc pipe supported at maybe 3-4 places with sprinkler heads installed duplicating the flow of one of the present circuits. This would be a complete pain but it is do-able.

 

[goof99]

It would seem that everybody is either speechless at my brilliant powers of analytical deduction or just struck dumb by my incredible stupidity. Be nice to know which. Comments either way will be accepted with aplomb.

I see a couple other threads with a similar problem but no followup on the solution, if any. Too bad really, be sort of nice and perhaps helpful to know what they finally did.

 

[Chris]

I think you could be right. Inside the city meter is a wheel that spins and if it is getting old it could be vibrating inside there. I have a city meter in my storage I abandoned from a job, I'll see if I can get it open.

What brand is your meter? It should say on the dial or what district do you have?

 

[goof99]

The plastic cover says BADGER METER. Serial or ID # 34146070. The meter face says Model 25 Recordall. To my uncertain knowledge it has been in place since we built the house in 1981. I've no memory of it being changed.

I will Google > how does a city water meter work<

 

[Chris]

The one I have in my shop is a Neptune and on the inlet side there is a plastic screen that is cone shaped and for the meter it is like a impeller in there. That could be loose.

 

[goof99]

Thanx for looking. One of my neighbors has a Neptune. I should think a worn or unbalanced rotor would act like mine does. I did find this sight which might at least indicate I am not totally crazy.

http://diy.stackexchange.com/questi...-my-water-meter-vibrate-when-water-is-flowing

I will next call the city water dept and request they inspect my meter - see what falls out from that. And let you know.

 

[IFIXH20]

Turn the meter and service entrance valve off, cut the water service between the meter and service entrance valve ( make cut above ground), open water meter fully and listen for vibration. I see no reason to set up a sprinkler system to test your meter.