Navien NPE-180A2 Installation Manual page 70

Multiple NPE-S2 Units:
●
DHW Supply Line
5.1.1 Piping Sizes and Considerations
When plumbing a cascade system, consider the
following pipe diameters and flow rates. Note that
flow rates above 6.6 ft/s may cause pipe erosion.
These specifications may vary depending on
installation conditions.
ΔT=54ºF
Qty
Flow rate (GPM)
1 7.19
2 14.38
3 21.57
4 28.77
5 35.96
6 43.15
7 50.34
8 57.5
9 64.72
10 71.92
11 79.11
12 86.30
13 93.49
70 Installing a Cascade System
Communication
Cable
[NPE-150S2/180S2/ 210S2/ 240S2]
Water Pipe
Velocity Diameter
(ft/s) (mm/in)
4.78 20A / in.
3
4
5.61 25A 1 in.
5.54 30A 1 / in.
1
4
40A 1
5.21 1 / in.
2
40A 1
6.53 / in.
1
2
4.49 50A 2 in.
5.24 50A 2 in.
6.00 50A 2 in.
4.39 65A 2 1 / in.
2
4.75 65A 2 / in.
1
2
5.34 65A 2 / in.
1
2
5.84 65A 2
1 / in.
2
6.33 65A 2 1 / in.
2
Gas Supply Line
Cold Water Supply Line
ΔT=54ºF
Qty
Flow rate (GPM)
14 100.68
15 107.87
16 115.07
17 122.26
18 129.45
19 136.64
20 143.83
21 151.02
22 158.21
23 165.41
24 172.60
25 179.79
26 186.98
27 194.17
28 201.36
29 208.56
30 215.75
The table above is based on model
Note
NPE-240A2.
Union
Ball Valve or Navien
Plumb Easy Valve
Check Valve
Faucet
Expansion Tank
Pressure Relief Valve
Water Pipe
Velocity
Diameter
(ft/s) (mm/in)
6.79 65A 2
1 / in.
2
5.11 80A 3 in.
5.44 80A 3 in.
5.81 80A 3 in.
6.14 80A 3 in.
6.46 80A 3 in.
6.83 80A 3 in.
4.06 100A 4 in.
4.25 100A 4 in.
4.45 100A 4 in.
4.65 100A 4 in.
4.85 100A 4 in.
5.05 100A 4 in.
5.24 100A 4 in.
5.44 100A 4 in.
5.61 100A 4 in.
5.81 100A 4 in.