Q: Do I really need a water pressure regulator?
A: Water lines in RVs should have no more than 60-65 psi. That is a very comfortable pressure for faucets and showers in your RV, could it handle more, probably but do you want to risk it? Here is the water pressure regulator I use (which is currently unavailable on Amazon a/o 1/8/2020. https://www.amazon.com/gp/product/B071DNFJBH But any of the ones that can regulate it and have a dial to see what the water pressure is fine. The ones I don’t like are the ones w/o a gauge.