Weil-McLain CGi Series 3 Installation And Maintenance Manual page 27

CG i
GAS-FIRED wATER BOILER- sERIEs a -
Boiler Manual
4d
Piping - low temperature systems
<conlinued)
Figure 22 Boiler-bypass piping - Zoning with
circulators - (Aitematlve to primary/
secondary piping Figures 20 and 21)
Figure 23 Boiler-bypass piping - Zoning wllh
zone valves - (Alternative to primary/
secondary piping Figures 20 and 21)
Cold
water
••
Effi
I I
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 in-
structions to the left for adjusting
valves)
8 Blend temperature gauge
r--------------f-zoN"e-2~---------+,.
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~-----------J
!
' ZONE1 '
f*
1 1
* •
i
5
~T-1
: it.....!
~---
--+1·
6
Cold
-M
~
, .
I I!!!
71024
71025
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
d osed-type expansion tank, pipe from top of air separato r to
tank fitting as in Figure 17. page 21).
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 expansio n tank, circulator or air separator.)
Part Number 550-142-780/0712 27