[terry and jo]

We've had a Watts 263A for a while now, and your target of 50 to 55 should be fine. However, I'd try to stay under 60 if possible. While most of the plumbing is not a problem, even at higher pressures because it is PEX line, the fittings are a different matter.

We lived in a small mobile home park once with darn high water pressure and I kept getting small leaks where the fittings went onto the faucet inlets. Even after getting a water pressure regulator on, I've had two occasions where a PEX fitting actually blew apart. Once it was the fitting where it hooked into the toilet, and another time was on one of the shower faucet inlets.

Terry