Part number 550-143-010/1021
22
GV90+
series
2
gas-fired water boiler – boiler manual
Figure 27
Installing GV90+ boiler in system with water
chiller
MINIMUM
Boiler loop pipe
size
GV90+3/4
GV90+5/6
1”
1¼”
Install water piping
(continued)
Water chiller systems
Pipe the boiler and water chiller as shown in Figure 27.
Install boiler, as shown, so chilled medium is piped in parallel
with heating boiler.
Use appropriate valves to prevent chilled medium from entering
boiler. See Figure 27 for typical installation of balancing valve
and check valve.
Install the flow/check valve in the boiler supply piping, as shown
in Figure 27, to prevent gravity circulation during the cooling
cycle.
If boiler is connected to heating coils located in air handling units
where they can be exposed to refrigerated air, use flow control
valves or other automatic means to prevent gravity circulation
during cooling cycle.
Balancing, when required
—
Substitute a memory-
stop valve for one of the isolation valves in each
zone to use the memory-stop valve for balancing
flow as well as isolation.
Zoning with zone valves
—
Provide a separate
24-volt transformer to power the zone valves. Size
the transformer to handle the total rated load of
all connected zone valves. Alternatively, use a zone
valve zone controller.
Do not use R & C connections for zone valve.
Zoning with circulators
— The GV90+ internal
system circulator cannot be removed from the
boiler for use as one of the zone circulators. It
must remain as shipped from the factory to allow
proper flow control inside the boiler. You will need
a circulator for each zone. Provide circulator relays
or circulator zone controller.
Chilled water systems often use closed-type expan-
sion tanks, as shown in Figure 27. DO NOT install
automatic air vents on these systems.
Legend
1 Isolation valves
2 Air separator
3 Expansion tank with tank fitting (piping shown for
application of a closed-type expansion tank)
5 System circulator
6 Flow/check valve
8 Boiler pressure/temperature gauge
16 Cold water fill line — see
for typical
components
17 Balancing valve
19 Chiller
20 Strainer
21 Check valve
22 System supply
23 System return