Re: Noisy PRV
Chances are your pressure regulating valve has a removable filter or strainer that should be cleaned periodically. That should be the first step.
After doing that ... turn on the water slightly and see if the noise continues.
If so .... with the water turned on slightly .... turn adjusting the screw slowly until noise disappears.
If it does not and only changes in sound you may have a faulty pressure reducing valve.
One thing to remember .... adjusting the screw changes the pressure and without a gauge you don't know what that pressure will be .... that's why you want to do this slowly with the water running slightly.
Alternatively...... likely you have a shutoff valve prior to and/or after the pressure reducing valve and they are of the washer variety, check them for a bad washer and make sure they are open all the way. If you narrow it down to a water shutoff valve and changing washers does not help replace them with a ball valve.
Hope this makes sense and helps.
"" an ounce of perception -- a pound of obscure "