Weil-McLain Gold CGi 2 Series Manual page 23

CGi
GOLD GAS-FIRED WATER BOILER — SERIES 2 —
4c
Water piping — multiple zones
Figure 18
1
Boiler isolation (balancing) valves
2
Flow/check valve
3
System or zone circulator
5
Zone valve
6
Drain valve
9
Relief valve
Part Number 550-110-710/1211
Zoning with circulators
— return water 130°F or higher.
For systems with possible low return-water temperature (such as converted gravity systems,
radiant heating systems and heat pump systems), refer to the special piping suggestions of
Figures 20 – 24 , as applies. Failure to prevent sustained low return water temperature to
the boiler could cause corrosion of the boiler sections, resulting in severe personal injury,
death or substantial property damage.
Boiler Manual
Figure 19
10
Automatic air vent (with diaphragm-type expansion tank), or con-
nect to tank fitting (closed-type expansion tank).
automatic air vent when using closed-type expansion tank. It would
allow air to leave the system, causing waterlogging of the expansion
tank.
11
Fill valve
12
Diaphragm-type or bladder-type expansion tank, if used (For
closed-type expansion tank, pipe from top of air separator to tank
fitting as in Figure 17 .)
13
Air separator and automatic vent, if used (Note that the fill valve
must always be connected to the expansion tank, regardless of loca-
tion of expansion tank circulator or air separator.
(continued)
Zoning with zone valves
— return water 130°F or higher.
DO NOT use an
23