high water pressure help

[miamichillin99]

This is my first post so please be kind. This is a great site so thank you to the admins and mods for supporting such an informative site.

I have water pressure of 90 psi measured using a Watts pressure gauge attached to a hose spigot. When I turn on any faucet or flush a toilet in the house the water pressure drops drastically to about 40 psi. If I turn on 2 faucets/toilets it goes down to 30 psi. 3 cold water taps and it's around 25 psi. All the cold water taps in the house and it goes to 19. Is this normal? I have a water pressure regulator, Watts N35B, which regulates between 25 and 75 psi but it had no impact on the 90 psi when I adjusted it. Strangely enough it did have an impact on the psi when at least one cold water tap is running.

Thanks in advance.

 

[IFIXH20]

Sounds like your PRV (pressure reducing valve) or your service entrance valve is bad. What type of whole house shutoff valve do you have?

 

[miamichillin99]

Thanks IFIXH20. The more I read the more I think it is the PRV. I did some testing adjusting the screw and I could get the pressure to go higher with running water but never could I get it below 40 when running. How hard is it to replace? I'm attaching some pics. I'm not sure if it's soldered or screwed on. Also the sutoff valve into the house is just downstream to the PRV.

 

[IFIXH20]

Someone did not do you any favor -- Do you have any soldering skills

 

[miamichillin99]

I've never done a pipe this thick but I have sweated smaller copper pipes. I only have a propane bernzomatic though. Do I need something stronger for this job? How about the rebuild kits? It's only 20 bucks. I'm very good at disassembling and reassembling all kinds of things.

 

[buhrly]

If you do replace it add unions on both sides. It will make it easier next time.