OK, take it for what it's worth: We had a similar problem, but it wasn't low pressure, it was high pressure and I had negleted to put our pressure reg inline. Now refuse to hookup water until the pressure reg is on the tap. As for low pressure, our reg is set for about 40 and have been at some places recently where their pressure was only 25 to 30 and no problems.
I did talk to a Tetford Tech after our problem and was told pressure shouldn't exceed 60 lbs because the shutoff couldn't handle high pressure.
Michelle & Ann
2018 Chevy 3500HD Crew Cab High Country DRW, D/A, 2016 RW39MB, Dual ACs, Auto Level, Auto Sat Dish, Stack W/D, King Sleep #, 17.5" Sailuns w/Disc, MORryde IS & Pin, Comfort Ride Hitch, 5.5 Onan, Res Fridge & Induction Cook Top