Pipe vibration when irrigation on

[rrauenza]

This problem is similar to another I saw posted here, so I thought I'd give this a try before digging into the problem trying random things...

When one particular sprinkler zone is turned on, the pipes vibrate at a very specific frequency -- sounds like a diesel truck idling outside our house. If I turn off the house valve, it stops. To me that shows obviously it is coming from the sprinklers, and shutting off the water to the house inhibits the vibration (there was no flow INTO the house - just closing the valve on a non-flowing pipe -- this will be clearer in the picture.)

I haven't measured the pressure yet, but can do that this weekend. The house I believe is at 50-60, the city pressure a little higher, maybe 80.

Here is the diagram, as I think the problem is related to the irrigation zone location relative to the house pressure reducer. The zone runs off of city pressure.

If you don't mind, I drew it up in google docs:

https://docs.google.com/drawings/d/1eY_71OD8G6Vxz5F-hkLwWqLahIzt5NaghjWm6wFua0w/edit?usp=sharing

The distance between the irrigation valve and the 3 way split is not very big, we're talking less than a foot. This used to be three valves, but was consolidated to a single valve. (The lawn isn't that big. One zone is plenty for the area - it has maybe a dozen sprayers.)

I was considering perhaps buying a bigger valve, as I've seen people say the valve size could be a factor. I was also considering putting a hammer arrester next to the sprinkler valve.

I'll also go put my ear next to the meter and see if there is vibration there as I've saw a reference in another post here that the meter could cause vibration as well.

Anything else I should check this weekend?

 

[rrauenza]

Sooo... I never would have thought to suspect the actual meter except for reading another thread here (http://www.plumbingforums.com/forum/f2/severe-continuous-pipe-vibration-when-valve-s-open-3555/)

I turned on the irrrigation zone again and listened to the meter -- I did here the noise there. But not surprised since it is connected to the entire water system and it could just be reverberating...

So I turned the zone off and turned on a few taps around the house to get the flow fairly high. Ah! The vibration seemed to return, but not as intense.

Seem unreasonable to contact the water company next?

 

[IFIXH20]

Before reducing to one zone (valve) did you notice the noise ? Is the noise/vibration present when the sprinkler system and serval house fixture are on at the same time ?

 

[rrauenza]

I don't recall if the noise was present (or not present) before consolidating the zones. I've ignored the noise for sometime because I expected it was some construction nearby. And the irrigation has been off all winter.

I turned on the zone, and another, and a bathtub and sink. The noise persisted. I've also turned on a few things except that particular zone and I get a milder version of the noise.

I dropped a note last night to our city public works and asked them to come check it out.

Rich

 

[rrauenza]

They came out today and replaced the meter. He said the previous one was pretty old and thought it likely the impeller was bad.

The vibration is greatly reduced now, but still somewhat present. Maybe there is still some air in the system from the replacement.

btw, FYI, he said it is common to see an increase in the water bill after replacing a very old meter, as they tend to run slow due to age.

 

[camaroderrick73]

I've had to in the past install a check valve at the service to eliminate that kind of noise. Maybe try that and see if it helps...