I see a 115 PSI water pressure at my home. Looks like my PRV is hosed. I am a complete newbie in plumbing, please take a look at the pictures and help me understand what I need to replace the PRV.

So I believe its a single union PRV. I bought a Zurn nr3xl to replace it. Upper joint seems to be soldered?? Bottom joint can probably be removed turning the union ring. Am I correct? Anything else that I need to know? Please also share what tools I need.


  • Hello, and welcome to Home Improvement. Looks like that upper joint is threaded as well. And, you should probably take our tour so you'll know how best to participate here. Aug 30, 2019 at 23:15
  • The upper joint is a threaded connection (inside and out) that either used green dope or leaked. Don't crush the copper pipe fitting....
    – Mazura
    Jan 28, 2020 at 19:51

1 Answer 1


A slight hack job, but you should not need a torch, unless the new valve does not have the same thread options.

Wrench big enough to grab the body of the valve itself. To begin with, hold it still.

Wrench to remove the union nut (first) while roundly cursing the installer and inspector who said "Yup, the ground is bonded across this thing" while not providing enough grounding cable to make replacing it easy. You don't want to remove that bonding wire from the pipe, is the thing....

Then a wrench the size of the wrench flats on the fitting above (to hold it still) while using the wrench on the valve itself to unscrew that (there appear to be internal pipe threads as well as the external union threads.)

Reverse the process to install the new valve.

  • Thank you sir, I hope it goes as easy as you make it sound :)
    – Sandy
    Aug 31, 2019 at 4:45
  • 1
    You may have to disassemble the valve to be able to turn it. They usually have a fairly strong spring but are not difficult if you back the pressure adjustment screw out. They do make rebuild kits that are much cheaper than replacing the valve.
    – Ed Beal
    Aug 31, 2019 at 15:11
  • Should OP take any special precautions to drain the line first given the rather high pressures involved?
    – Freiheit
    Jan 28, 2020 at 18:17

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.