RV water lines/fittings are typically rated to 80 psi. We have stopped at a campground where the owner advised folks checking in to be sure to use a pressure regulator because the city supplied water was at 150 psi. We stayed at another campground once on a mountainside (in West Virginia). Water pressure was fine up at the top, but if you got a site down near the bottom of the campground, the water pressure was, um, a bit high. Hooked up the hose, and with no nozzle at all on it, it launched a full hose stream of water that hit the ground over 50 feet away.
And the others are right, 25 psi will have your showers and faucets merely dribbling. You won't like it at all.