Leaking Pipes Joints

Install a pressure reducer, dude! You're running twice what you should be...

Most household fixtures are not rated for120 PSI. Besides havering trouble with your fittings, I'm surprised that you aren't damaging your fixtures.

Have you considered a Pressure Reducing Valve to bring the pressure down to something reasonable, like 60 PSI?

Everybody immediately jumps up and tells you that you have to have a pressure reducer. I have 120 psi water pressure and have had hardly any problems. I have one hose bib that I have a problem keeping washers in, but that hose bib is over

As far as the leaks, you might try using the liquid pipe dope. Put on a good thick coat and screw the threads up tight.

Bill

Step 1: Install a Pressure Reducer. No reason to be above 60 or so PSI. Most are about 50 PSI

The leaks are not due to pressure, a proper joint can easily handle it. Make sure the connections are clean, no dents or dings, tape is wrapped properly.

I used the liquid teflon pipe dope on those fittings in my bathroom last week - and the fittings leaked. The heavy (pink) teflon tape would likely be a better choice. I solved my problem with regular teflon tape.

And NEVER use "compression fittings" - you know, the ones with the brass "olive" that gets cranked onto the pipe by turning the compression nut. They WILL seepwhen used on hard copper lines - almost guaranteed. You might never see a drip, but months later the connection is all green.

That was the first thing I thought.

I agree that the pressure, while higher than normal, higher than I would ever have, isn't the source of his problem. And there are some mysteries there, like why there is a washer or seal of some kind when going from copper to brass. Teflon tape should work, but I also agree with your suggestion of trying pipe dope instead. More likely, he's doing something wrong, like not making them up tight enough.

You will note that I mentioned fixtures in my response. I acknowledged that the OP was have problems with his fittings, but I did not say that the 120 PSI was the cause of the problems.

My point was that 120 PSI pressure can cause problems with many fixtures, from toilet fill valves to washing machine solenoids.

If this site is correct, then the Uniform Plumbing Code requires PRV in specific situations.

"The Uniform Plumbing Code and PRV

The Uniform Plumbing Code requires a PRV be installed if the water pressure exceeds 80 PSI at the time the home is built, or for any inspection of a plumbing task that involves a water test thereafter resulting in high-pressure. "

If a PRV is required at >80 PSI for new builds and inspections, then a PRV makes sense in *any* situation where the pressure exceeds 80 PSI.

One could argue that in older homes, a PRV is even more important because fixtures and/or fittings may not meet the more stringent modern codes.

Typical PRV on water heater is set to 150psi, so no, 120psi water pressure will not cause the water heater valve to release.

What this idiot dont realize is that if there is a huge fire in the area, the water pressure will drop while the Fire Dept has open hydrants. As soon as they shut the last hydrant, that pressure will increase to over 200psi for a few seconds. At that time, weak pipes will balloon, weak joints will explode apart, wash machine hoses will rupture, valves will fail, toilet tanks may shatter, and water heaters & boiler tanks may explode if the PRV is not working properly.

Teflon tape is fine, if wrapped carefully in the right direction. I've had better luck with tape than dope. YMMV.

My guess, you need a bigger wrench.

Tape and one more turn than you think.

Sorry, no ff will slam any valves shut. Please cite an example of your post.