Water system testing question

I quit running on city water hook up a few years ago. I run only on my fresh water tank and on-board pump. Once at a KOA the manager told me to be sure to use a regulator because the water pressure at the campground was around 70 psi. He said for most campers that is too much and would blow the lines out. I had only a simply regulator that screws on the end of a garden hose so decided not to take any chances on blowing out my lines. So I filled the fresh water tank and pumped from it. And.... I've been doing that ever since. As long as the on-board water pump pressure does not cause any leaks, I think that about the expected pressure. Any more and you're taking a risk.