Originally Posted by ceedog
RV plumbing is typically designed to handle 30psi.
What is the source of this information? Can you post a link to it if there is one?
I have never had a problem caused by high water pressure in any RV I have owned.
At my home, the street pressure is 110psi. I have a pressure reducing valve inside set at 75psi for everything inside the house. My water for outside is connected before the PRV, so I have 110psi at all of my outside hose bibs. All of my RVs have been connected to 110psi for extended periods of time — months — with no issues — ever. The only reason I have a PRV on my home system is to reduce the level of noise created in the pipes and at toilet fill valves and solenoid controlled appliances due to the high flow generated by high pressure.
I have never used a PRV at any campgrounds, either. However, if I was concerned enough and decided to use a PRV for my RV, I would set it to somewhere between 55psi and 65psi. Every time your RV’s tank-type water heater (the OP doesn’t have this) heats cold water to make it hot, the pressure in the entire system — both hot and cold sides — is easily going to exceed 65psi, and quite often take it all of the way up to 150psi where the temperature and pressure relief valve on the water heater will begin to weep to keep the pressure at or just below 150psi.