Part Number 550-142-302/0520
CGi
SERIES 4 — GAS-FIRED WATER BOILER —
Boiler Manual
25
4d
Piping — low temperature systems
(continued)
1
Boiler isolation (balancing) valves
2
Flow/check valve
3
System or zone circulator
4
System temperature gauges
5
Zone valve
6
Drain valve
7
System temperature valves (see instruc-
tions to the left for adjusting valves)
8
Blend temperature gauge
9
Relief valve
10
Automatic air vent (with diaphragm-type expansion tank), or
connect to tank fitting (closed-type expansion tank).
DO NOT
use an 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
location of expansion tank, circulator or air separator.)
Figure 20
Primary/secondary piping
Zoning with circulators
Figure 21
Primary/secondary piping
Zoning with zone valves
