Install Instructions

IM-PR 566442 1114 (Design Manual)
38
1.9.4 Circulator placement relative to the expansion tank
A common mistake in installations is incorrect placement of the expansion tank relative to the circulator.
The recommended practice is placement of the expansion tank on the suction side of the circulator on
the primary loop. Pumping away from the expansion tank will enable the distribution system to operate
at a higher pressure, which will help resist the formation of air bubbles in the fluid as well as help avoid
cavitation (formation and implosion of air at the impeller due to low fluid pressure) that could otherwise
damage the pump. Also, maintain at least 10 to 12 pipe diameters separation from the expansion tank to
the inlet side of the pump.
Figure 1-30 Pumping away from the expansion tank helps maintain a higher system pressure and increase
the life expectancy of pumps
30 psi
30 psi
30 psi
40 psi
Pump O
Pump On
20 psi
Pump On
30 psi
30 psi
Pump O
30 psi