Weil-McLain CGi 4 Series Manual page 27

CGi
SERIES 4 — GAS-FIRED WATER BOILER —
4d
Piping — low temperature systems
Figure 22 Boiler-bypass piping — Zoning with
Boiler isolation (balancing) valves
1
Flow/check valve
2
System or zone circulator
3
4 System temperature gauges
Zone valve
5
6 Drain valve
System temperature valves (see
7
instructions to the left for adjusting
valves)
8 Blend temperature gauge
Part Number 550-142-302/0124
Boiler Manual
circulators — (Alternative to primary/
secondary piping Figures 20 and 21)
Figure 23 Boiler-bypass piping — Zoning with
zone valves — (Alternative to primary/
secondary piping Figures 20 and 21)
Relief valve
9
Automatic air vent (with diaphragm-type expansion tank),
10
or connect to tank fitting (closed-type expansion tank).
use an automatic air vent when using closed-type
NOT
expansion tank. It would allow air to leave the system,
causing waterlogging of the expansion tank.
11 Fill valve
Diaphragm-type or bladder-type expansion tank, if used
12
(For closed-type expansion tank, pipe from top of air sepa-
rator to tank fitting as in
Air separator and automatic vent, if used (Note that the fill
13
valve must always be connected to the expansion tank,
regardless of location of expansion tank, circulator or air
separator.)
(continued)
page 21).
Figure 17,
DO
27