Correct pressure for pressurized fresh water tank?

[seanobrien]

Opened the air valve.  Filled with water. Closed the air valve and pumped to 20.  How high should it be?  water flows ok.  Don't want to blow the tank but 20 seems low.  Any thoughts?

[DaveVA78Chieftain]

The 1968 manual in the Free Manuals section of the Members Area of the site indicates 45 lbs max for water pressure.

Dave