Thanks for all the info//support.
The water pressure is now a reasonable 50 psi.
However, when the water faucets, etc are turned on, my daughter noticed a noise in one room. It seems that when the water passes through the newly installed pressure regulator
There is a noticeable "humming noise" that we never noticed before.
Is the water pressure regulator supposed to "hum" when water flows through it or is this a sign of a failing regulator or something else?
Thanks again for your help.
Ron

Sometimes you can 'tweak it' by adjusting ever so slightly to stop the hum. Sometimes the hum is not the prv but in a toilet fill valve.