I've always heard 50-60 psi. But, my previous home had no regulator, and the
pressure was measured at 100-ish. In 20 years, the worst problem we had was
noisy pipes when the kitchen sink was turned on. No premature wear that I
was aware of, unless having the rebuild the Delta kitchen faucet twice ($10,
20 minutes), was caused by high pressure.



For most homes, it is not just a matter of setting the regulator to
get the pressure you want. The size of the pipes and their various
branches is a key factor.

Even if you have your regulator maxed out, the shower is not going to
be vary powerful if it's plumbed with 1/2 " pipe or is located a long
distance from the house inlet.

Beachcomber