Page 15
KN INSTALLATION AND OPERATION INSTRUCTIONS
Water piping
(continued)
Figure 11
Suggested piping — multiple boilers — primary/secondary piping, reverse-return boiler headers
Multiple boilers, primary/secondary
Sizing and flow control
Size circulators to provide the flow needed for the individual zones.
Provide flow/check valves where shown to prevent gravity circulation or
forced flow in idle zones.
DHW operation, when required
The piping shown throughout this manual allows for domestic water
heating without flow through the heating loop(s). This is important for
summertime operation of DHW tanks.
Make sure to incorporate flow/check valves as shown. These prevent forced
flow in idle zones.
L
egend
• • • • • • •
1
K N
boiler
2
Boiler circulator
3
System circulator
5
Indirect-fired DHW tank
(when used)
6
DHW circulator
7
Flow/check valve
8
Cold water fill line
9
Expansion tank (shown with diaphragm-type — see
page 12 for piping a closed-type tank) Expansion tank
(shown with diaphragm-type — see page 12 for piping
a closed-type tank)
10
Air separator with automatic air vent (Replace air vent
with piping to the tank fitting on closed-type expansion
systems.)
11
Low water cut-off (when required)
12
Extra high limit (when required)
16
Boiler postpurge circulator (see page 11)
K N-2
only
17
Header sensor, required
Isolation valve
Temperature gauge
5
2
3
4
5
8
9
10
11
5
4
20010
1
1
1
1
2
2
2
7
7
7
7
7
12
DHW tappings
12" max
(305 mm)
Supply
to system
Return
from system
17
16
16
16
16