Weil-McLain GV90+ - Manual (Page 22)

Part number 550-142-054/0411
GV90+
gas
-
fired water boiler
— Boiler Manual
22
Figure 27 Installing GV90+ boiler in system with
water chiller
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 trans-
former to handle the total rated load of all connected zone
valves. Alternatively, use a zone valve zone controller.
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 expansion
tanks, as shown in Figure 27. DO NOT install automatic
air vents on these systems.
MINIMUM
Boiler loop pipe size
GV90+3/4
GV90+5/6 1”
1¼”
Install water piping
(continued)
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 Figure 15, page 14 for typical
components
17 Balancing valve
19 Chiller
20 Strainer
21 Check valve
22 System supply
23 System return