Raypak MVB 503-2003 User Manual
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Table F: Heater Rates of Flow and Pressure Drops
20°F T
30°F T
40°F T
Min. Flow
Max. Flow
Model
No.
gpm
P (ft)
gpm
P (ft)
gpm
P (ft)
gpm
P (ft)
T gpm
P (ft)
T
503
44
2.8
29
1.4
N/A
N/A
25
1.1
35
100
11.3
9
753
65
6.4
44
3.1
33
1.9
33
1.9
40
100
13.8
13
1003
87
12.0
58
6.0
43
3.7
43
3.7
40
113
18.6
15
1253
109
20.9
73
10.2
54
6.2
54
6.2
40
113
22.2
19
1503
N/A
N/A
87
16.0
65
9.5
65
9.5
40
113
25.5
23
1753
N/A
N/A
102
22.5
76
13.4
76
13.4
40
113
27.2
27
2003
N/A
N/A
116
32.0
87
18.9
87
18.9
40
116
32.0
30
Notes: Basis for minimum flow is ∆T . Basis for maximum flow is gpm.
Piping
All high points should be vented. A heater installed
above radiation level must be provided with a low wa-
ter cut-off device (sales order option F-10). This
heater, when used in connection with a refrigeration
system, must be installed so that the chilled medium is
piped in parallel with the heater with appropriate
valves to pre-vent the chilled medium from entering
the heater.
The piping system of a hot water heater connected to
heating coils located in air handling units where they
may be exposed to circulating refrigerated air, must be
equipped with flow control valves or other automatic
means to prevent gravity circulation of the heater
water during the cooling cycle. It is highly recommend-
ed that the piping be insulated.
Air-Separation/Expansion Tank
All heaters should be equipped with a properly sized
expansion tank and air separator fitting as shown in
Fig. 11.
Fig. 11: Air-Separation/Expansion Tank
*
THERMOSTAT OR
SYSTEM SENSOR
Fig. 12: Single Heater - Low-Temperature (Heat Pump)
Application with Primary/Secondary Piping
*
THERMOSTAT OR
SYSTEM SENSOR
Fig. 13: Dual Heaters (Reverse/Return)
with Primary/Secondary Piping
*Maximum 4 times the pipe diameter or 12”, whichever is less.
*Maximum 4 times the pipe diameter or 12”, whichever is less.