Circulator Sizing; Pressure Relief Valve - Westinghouse Premium WGRT 199 Series Installation, Start-Up, Maintenance, Parts, Warranty

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F. Circulator Sizing
Figure 17 - Pressure Drop through the Heat Exchanger
Number of
Flow Rate
Units
(GPM)
1
5
2
10
3 16
4
21
5
26
6 31
7
36
8 41
9 47
10
52
11 57
12 62
13
67
14 72
15
78
16
83
17 88
18
93
Table 13 - Recommended Water Pipe Size
NOTE: The above pipe sizes are recommended based on water velocity of 5 ft/s and a maximum water temperature of 140
G. Pressure Relief Valve
An external pressure relief valve must be installed on this water heater. When installing, observe the following guidelines. Failure to comply
with these guidelines can result in substantial property damage, personal injury, or death.
This water heater must be provided with an approved 150 psi, ¾" ASME HV Valve that must be installed on the DHW outlet line. The 150 psi
Pressure Relief Valve must be installed on the DHW outlet line to ensure a compliant installation and safe operation.
This water heater has a high-temperature shut-off switch built in as a standard safety feature. Therefore, a "pressure only" relief valve is
whl-004 Rev. 000 Rel. 013 Date 5.1.18
o
∆T = 77 F
Water
Pipe Dia. Flow Rate
Velocity
(In.) (GPM)
(ft/s)
3/4
3.75
1
4.22
4.05 1 1/4
3.75
1 1/2
4.69
3.17
3.69
2
4.22
4.75
3.38
3.72
4.05 2 1/2
4.39
4.73
3.52
3.75
3
3.99
4.22
o
∆T = 45 F
Water
Pipe Dia.
Velocity
(In.)
(ft/s)
1
9 3.61
18 3.21
1 1/2
27 4.82
35 3.61
2
44 4.52
53 3.47
2 1/2
62 4.05
71 4.62
80 3.61
88 4.01
3
97 4.42
106 4.82
115 3.83
124 4.13
3 1/2
133 4.42
142 4.72
150 3.84
4
159 4.06
o
∆T = 35 F
Water
Flow Rate Pipe Dia.
Velocity
(GPM)
(ft/s)
11 4.64
23 4.13
34 3.48
45 4.64
57 3.72
68 4.46
80 3.61
91 4.13
102 4.64
114 3.79
125 4.17
136 4.55
148 4.93
159 4.06
171 4.35
182 4.64
193 4.94
205 5.23
o
F.
(In.)
1
1 1/2
2
2 1/2
3
3 1/2
4