Domestic water pressure isn’t supposed to exceed 80PSI. Not that we pay attention to the IRC but it calls for pressure reducing valves for domestic pressure over 80psi. I know pressure relief valves around here at the plumbing houses and such all start to blow of at 80psi.
Furthermore, all the fill valves and such are rated at 80psi max. While that’s not bursting/bypass pressure rating, if you see 90-120 all the time, someone has royally effed up.
I understand your concern and I had it until I realized that the relief valves on homes were always before the main home shutoff and after the utility shutoff. Obviously, it’s builder and AHJ dependent. 99% of my inspections are the same builder. The few I do outside of the villages seem to be the same.
Utility Shutoff–>PRV(reducing or relief)—>Domestic shutoff–>hosebibs and the rest of the home.
Not the case in many many homes in my area. In fact, my home. I love washing my truck on the city pressure 
This is a good topic. It touches on that dilemma we all have to deal with: how far do we go beyond the SOP, if at all. If the home has a pressure regulator, I point it out and tell them what it does and why they shouldn’t touch it unless they’re a plumber. If the home does not have one, I recommend one. It’s also too easy for we inspectors to get volume and pressure discussions crossed up, never mind the client. I have a water pressure gauge, but like the infrared and the voltmeter, I use it as a super sense, not as a measuring/reporting device.
Love it. 
Probably 95% of the homes in my area are on wells. I don’t do either flow or pressure testing. 99% of the time the RE agents recommends well testing by a well company. My pressure testing consist of turning on multiple faucets, flushing toilets etc…to see if the pressure is reduced. It either does or doesn’t.
I call that flow. I do a lot of wells and my “pressure testing” is the pressure tank psi and the pressure switch settings with one of my two certified air gauges which don’t agree (so much for “certified”)
Yep, I have yet to meet the inspector that does strictly SoP inspections.
Yes. My second one was oil filled. The store replaced it because they couldnt explain why it failed so quickly.
This third one continues to work. I try to remember to run the valve first before attaching the tester.
