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KN INSTALLATION AND OPERATION INSTRUCTIONS
Water piping
(continued)
Figure 13
Suggested piping — boilers connected to chilled water systems
Chilled water systems
General
Provide the piping components shown in Figure 13 when
connecting a boiler to a chilled water system. The check valve
(item 4) prevents chilled water from entering the boiler loop.
Sizing and flow control
Size the system circulator to handle the flow needs of all zones.
If using variable speed control of the system circulator, ensure
that the flow never drops below the total minimum for all
boilers connected.
The boiler loop can be any of the designs in this manual, or per
standard engineering practices.
Use the balancing valve to adjust the boiler loop flow.
Expansion tank/air control
Chilled water systems generally use closed-type expansion
tanks. DO NOT use automatic air vents in these systems. All air
must be return to the expansion tank for the system to operate
reliably.
If the boiler loop is connected to air handling units
that use chilled water, install flow control devices to
prevent gravity circulation in the boiler loop during
the cooling cycle in the air handling units.
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