Installation Guide
3
GENERAL SAFETY
SPECIFICATIONS
EXPANSION TANKS FOR HOT WATER HEATERS
Many local codes require back ow preventers. Since this seals
off the system an expansion tank is required or the relief valve
will discharge on every heating cycle. The thermal expansion
tanks eliminate this wasteful, costly and dangerous practice. The
thermal expansion tank is certied to ANSI/NSF 61° DHot, but
are suitable for temperatures up to of 200° F and pressures to
150 PSI. DO NOT USE A STANDARD TANK. The sizing chart
will allow you to choose the correct size expansion tank for your
application.
PURPOSE OF EXPANSION TANKS
When water is heated it expands. Provision must be made for
this expansion in a closed hot water system. This precharged
diaphragm tank stores the expanded hot water then returns water
to the system when the temperature drops.
Figure 1. Typical Expansion Tank Conguration