[EDIT2] (at top to make sure visibility) All good, as explained in one of the posts. I shouldn't expect pressure regulator to work directly at faucet. (Use tee or splitter) Here is video https://youtu.be/gp4aquT19LA
[Just started looking into drip irrigation] I'm using rainbird 25PSI pressure regulator along with pressure guage. (https://www.amazon.com/Rain-Bird-HT07525PSI-Irrigation-Regulator/dp/B0049C5FZA)
Pressure guage measures about 70PSI without regulator (directly at garden faucet), however this doesn't really change even after using pressure regulator.
Am I misunderstanding pressure regulator? or is guauge/regulator broken?
[EDIT] Here is what I'm talking about (in both cases it reads about 60PSI):
Pex is rated at 120 psi at hot water temperatures and only 160 psi at room temperature. So I seriously doubt that.
Rated pressure != burst pressure. I would expect a line rated at 160PSI line pressure to withstand at least 200PSI before bursting.
Water hammer can drastically increase line pressure; a line rated at 160PSI should be able to handle the transient pressure spikes that commonly occur in a 160PSI line.
Deliberately pushing 200PSI into a line rated for 160PSI is certainly not safe or acceptable, but I wouldn't be surprised to see it hold, and I would be surprised to see it fail.