i always use 15 or 16 lb cap.....what they mean is it would be better with less pressure in case there is a weak spot after 50 years, but honestly if it gets a hole it needed to be redone anyway.....you get 3 degrees of temperature per pound of pressure....in other words, water boils at 212 degrees so with a 7 lb. Cap you are gaining 21 extra degrees before you boil over.....which would be 233 degrees before it spewed.....16 lb. Cap will get you 48 degrees which is about 260 degrees.....just so you know
