by Larry Richardson
I've written before about the need to provide for thermal expansion
in a domestic hot water system. A visible clue might be a weepy
relief valve.
Not only is it important to provide for hot water expansion within
the system for safety reasons since the relief valve is not designed
for this purpose, but it is important for product durability as
well.
If you have a customer who complains about his water heater not
lasting, and you know the anode rod is being maintained, consider
a thermal expansion tank. In a closed system, as the heated water
expands without a place to go, the walls of the water vessel are
subjected to tremendous stress. That stress may weaken the welds
or seams and eventually lead to pre-mature failure.
Yaun company stocks Amtrol's model ST12 tank that can handle tanks
sizes to 120 gallons, has a ¾" MIP connection and
is preset at the factory to 40 P.S.I. Install this tank in the
cold water inlet line to the tank
Consider a domestic thermal expansion tank as good "preventative
medicine."