47
D. Special Situation Piping Installation
Requirements
Observe the following guidelines when making the
actual installation of the boiler piping for special
situations:
1. Systems containing high level of dissolved
oxygen
– Many hydronic systems contain enough
dissolved oxygen to cause severe corrosion damage
to Apex boiler heat exchanger. Some examples
include but not limited to:
•
Radiant systems employing tubing without
oxygen barrier
• Systems with routine additions of fresh water
• Systems open to atmosphere
If the boiler is used in such a system, it must be
separated from oxygenated water being heated
with a heat exchanger as shown in Figures 22A and
22B. Consult the heat exchanger manufacturer for
proper heat exchanger sizing as well as flow and
temperature requirements. All components on the
oxygenated side of the heat exchanger, such as the
pump and expansion tank, must be designed for use
in oxygenated water.
Table 15: Multiple Boiler Water Manifold Sizing
Boiler Model
Number of Units
2
3
4
5
6
7
8
Recommended Minimum Common
Water Manifold Size (NPT)
APX425
2½”
3”
3”
4”
5”
5”
5”
APX525
3”
4”
4”
5”
5”
6”
6”
APX625
3”
4”
5”
5”
6”
6”
6”
APX725
4”
4”
5”
6”
6”
8”
8”
APX825
4”
5”
5”
6”
6”
8”
8”
VI. Water Piping and Trim
D. Special Situation Piping Installation Requirements (continued)
2. Piping with a Chiller
- If the boiler is used in
conjunction with a chiller, pipe the boiler and chiller
in parallel. Use isolation valves to prevent chilled
water from entering the boiler.
3. Boiler Piping with Air Handlers
- Where the
boiler is connected to air handlers through which
refrigerated air passes, use flow control valves in the
boiler piping or other automatic means to prevent
gravity circulation during the cooling cycle.
Figure 22A: Isolation of the Boiler From Oxygenated Water with A Plate Heat Exchanger
(IWH Piped as Part of Boiler Piping)
Summary of Contents for APEX
Page 57: ...57 VIII Electrical continued Figure 26 Ladder Diagram ...
Page 58: ...58 VIII Electrical continued ...
Page 59: ...59 Figure 27 Wiring Connections Diagram VIII Electrical continued ...
Page 105: ...105 ...
Page 109: ...109 XIII Repair Parts continued APX625 APX725 and APX825 APX825 shown ...
Page 112: ...112 XIII Repair Parts continued APX425 and APX525 ...
Page 114: ...114 XIII Repair Parts continued APX625 APX725 and APX825 ...
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