Shaking pipes - new PRV

[azita]

I installed a Pressure Reducing Valve yesterday (had pressure between 80-90 in the day). I also installed a Thermal expansion tank to accommodate for having a closed system with the PRV. I set the PRV to 65.

I've been experiencing pipes shaking and vibrating since installing the PRV. The pressure gauge after the PRV shakes violently between 60 and 100 PSI and the pipes make noise. It seems to happen sometimes (though not always) when a toilet is flushed or someone opens a sink. Can't really put my finger on exactly what causes it.

When I have been able to watch it happen, I have closed off the flow on the main before the PRV and then slowly opened it and the shaking stops...

Any idea what's going on?

 

[azita]

It seems to consistently happen when I turn on the sinks on the top floor and especially when I flush the upstairs toilets. Main floor toilet and sink is less of an issue.

 

[Mr_David]

Is your main shut off valve a ball valve or a gate. make sure it's open 100%.

Do you have irrigation sprinkler zone valves. I had some ZV's cause the same thing a couple weeks ago. isolated the 4 ZV group and it stopped.

Is the PRV install in the right direction. If it's a double union it's real easy to install backwards.

Check ball cocks/fill valves in the toilets. It could be the reduced pressure is making them operate out of the norm

 

[frodo]

did you install any type of valve?

the prv has an arrow which way is te arrow pointing?

where did you put the expansion tank ?

how did you "set" the prv pressure ?

drop the psi outgoing prv to 50 psi

with a prv, your psi should not fluctuate from 60 to 100

 

[KULTULZ]

The pressure gauge after the PRV shakes violently between 60 and 100 PSI and the pipes make noise.

What air pressure did you set the expansion tank at?

 

[azita]

Thanks for the responses.

The expansion tank is on the cold water side of the water heater line, about a foot and a half above the heater. It is set at 60 psi, charged before I installed it.

The arrow on the prv is pointing in the direction of flow, off the street and towards the house. I set it by a screw on the top of the unit.

I have ball valves, one right before the prv and one right after. They are all the way open. But when the pipes shake, I can stop it by slightly closing the valve right before the prv.

As for the sprinklers. I do have some but the pipe going to them is shut off for the winter.

 

[KULTULZ]

Originally Posted by azita View Post

The pressure gauge after the PRV shakes violently between 60 and 100 PSI and the pipes make noise.

R U saying that after the pressure valve install, the water pressure is sometimes over 60PSI?

 

[azita]

R U saying that after the pressure valve install, the water pressure is sometimes over 60PSI?

The gauge right after the prv jumps all over the place when the pipes are shaking. But I just watched the gauge more closely and it seems to bounce between 60 and 0 super fast.

 

[KULTULZ]

The gauge right after the prv jumps all over the place when the pipes are shaking. But I just watched the gauge more closely and it seems to bounce between 60 and 0 super fast.

It seems to me... ... (and I am not a professional) that the problem is associated with the PRV install (bad valve or result of install). The expansion tank has to be set at the delivery pressure (you said you set the PRV @ 65PSI).

Do you have floppy pipes?

 

[frodo]

set prv at 50 psi...not 65

 

[KULTULZ]

set prv at 50 psi...not 65

Start as frodo has suggested @ 50PSI and match the expansion tank to 50PSI.

It may be that the expansion tank pressure is set too high and as the PRV attempts to regulate pressure, the excess pressure may not have a place to go (exp tank) as the tank pressure is too high to accept any excess pressure causing the PRV disc to chatter.

Did you mention make and model of PRV you installed?

 

[azita]

Well, I replaced the PRV with a new one and it worked fine for about 12 hours. Then more shaking. I found a similar complain in the review of the thing on Home Depot's website and this is the vendor response:

We apologize for the issue you are experiencing with your SharkBite Pressure Regulator. The Chatter or Hammering is generally caused by low-flow high inlet pressure, where you have a high incoming pressure and are drawing a very low flow, IE Flushing a toilet. Or it can be caused by High-flow low pressure where your inlet water pressure is close to the pressure setting of the valve and in high demand scenarios, IE Taking 2 showers running the dishwasher and washing machine together. We recommend that you adjust the pressure set net up or down 1 full turn from the factory setting of 45 PSI, this usually fixes the issue, if you are still having trouble please call our customer service line at 1-877-700-4242 and we will be happy to help you with this issue and resolve.

I set the PRV to 50 PSI and so far, no shaking. But we will see. It always seems to start out calm. Anyone heard of problems like this with other PRVs?

 

[voletl]

SharkBite....there's your problem

 

[frodo]

SharkBite....there's your problem

buy a WATTS prv and be done with it for years and years

 

[Mr_David]

My comment before I got to the
"We apologize for the issue you are experiencing with your SharkBite Pressure Regulator"
was going to be something like this;

sometimes the neoprene washer the seals against a seat in the PRV is loose or not properly setting in it's cup. this can cause it to vibrate when it is barely open.
Don't have any experience with sharkbite regulators, but I can image they are not very well built. Watts and Wilkens/ZURN both make a good PRV.

 

[azita]

Thanks. I'm looking to swap it out this week with a watts. How do I choose between their many options?

 

[Mr_David]

I can't help you with the watts . I install Zurn / Wilkens. The 600 are better than the 70's, other option are double union or threaded connection. just look at the specs and see what's better for you.