What is the best water pressure coming into the RV?

We opened up our camper this weekend and hooked up the water with an inline regulator. After flushing the water system, I started working on something eles and the outside shower faucet handle blow off the faucet. Luckly I had the door open from flushing and no water entered the unit. I figure the regulator went bad,and I have no idea what my supply pressure was. Not many people were at camp and I'd say the pressure was pretty high. In hindsight the pressure when flushing was higher than normal. I'm replacing the regulator with one that has a gauge.
Live and learn or read forums and learn from others!
Jim