I installed a water softener in our house, and the rubber gaskets kept on blowing out. I suspected the pressure was too high, so bought a meter and measured it at over 110 psi. I then installed a Watts pressure reducing valve near the main shutoff and brought the pressure down to 40-50 psi. The water softener gaskets are handling the lower pressure just fine, but now we are hearing a humming noise in the pipes whenever a faucet anywhere in the house is turned on. It stops when the faucet is turned off. Is this just a typical noise we should get used to, or is there a fix for this?
Thank you.

You have a vibrating, loose washer somewhere. Open a faucet and start touching every supply line you can reach, you should be able to feel the vibrating. Then come back and tell us where it is, probably still an issue with the softner so start there.

Dear ballengerb1
Thank you very much for the suggestions.
I isolated the water softener by turning off the shutoffs and opening the bypass pipe, but still get the humming. It seems the most vibration occurs close to the PRV. Could there be a washer in the PRV that is vibrating? The vibration occurs whenever any faucet is opened. Would a faucet washer vibrate even when the faucet is closed?
I'm not sure where other washers might be located.

Dear ballengerb1
Thank you very much for the suggestions.
I isolated the water softener by turning off the shutoffs and opening the bypass pipe, but still get the humming. It seems the most vibration occurs close to the PRV. Could there be a washer in the PRV that is vibrating? The vibration occurs whenever any faucet is opened. Would a faucet washer vibrate even when the faucet is closed?
I'm not sure where other washers might be located.

Do you feel any tingle or vibration directly off the prv

PROBLEM SOLVED!!
In thinking about "ballengerb1's" answer, I went outside and turned on all the outside spigots... a lot of air was trapped in one of the lines. Came in, and there is no more vibration/hum! The outside faucets were the only ones I didn't purge after turning off the water for the PRV install. Water softener is back on-line, too. Thanks for your help, it narrowed my search and helped me solve the problem. I like this website!! Thanks ballengerb1

Glad to be of assistance.