Burnham Apex APX399 Installation, Operating And Service Instructions page 53

Vi. Water Piping and Trim
Figure 38B: isolation of the Boiler From Oxygenated Water with a Plate Heat Exchanger
E.
Multiple Boiler Installation Water Piping - See Table 17
and Figures 39B and 40B.
1. Refer to this Section of this manual for:
a. Installation of Factory Supplied Piping and Trim
Components for an individual module (boiler).
b. Regarding an individual module (boiler) piping
system specific details.
c. Selection criteria for individual module (boiler)
space heating and/or DHW circulators.
E. Multiple Boiler Installation Water Piping (continued)
(iWH Piped Off System Header)
2. For installations where indirect domestic hot water
heater is combined with space heating, the Alliance
SL™ model must be piped as a separate heating
zone off the system header. The circulator must be
sized based on the Alliance SL™ model coil flow and
combined coil pressure drop and the zone piping total
equivalent length. Refer to Alliance SL™ Indirect
Water Heater literature for a specific model coil flow
and pressure drop. Refer to Table 18 and Figures 40A
and 40B.
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