Thump, Thump sound from the water pipe

[Liang]

Recently there is strange vibrating sound from the basement when I use washing machine, or (some) toilets, or showers. I recorded the sound and created a Youtube link (hopefully you could play it!). It seems the sound is from segment where the city water line to the main shutoff valve and PRV. First I thought it is water hammer and so I installed two water hammer arrestors to the washing machine. The sound still remains. I noticed that the sound comes when the water is running toward the washing machine/faucets, not when we shut off the water. My PRV seems OK, at least my water pressure is around 50psi. Any idea?

Any help would be much appreciated. Stay safe!

 

[Plumbs]

You need to replace or rebuild your prv. Just because it looks fine on the outside and the pressure is good doesn't mean the prv is good.

 

[Sponsor]

 

[Reach4]

You may be able to work around your PRV problem by changing the set pressure up or down.

To set the pressure, dribble water from a faucet, and watch the pressure gauge as you adjust.